oak

/oʊk/

/əʊk/

Other forms: oaks

An oak is a tree that typically sheds its leaves in the winter and grows acorns as fruit. If you get hit on the head with an acorn, you are probably standing under an oak.

There are many species of oaks, a few of which are evergreen, keeping their leaves all year, but most have bright leaves in the fall and are bare for the winter months. An oak table or oak desk is made from the sturdy wood of an oak tree. The strength of oaks has inspired several countries to adopt them as symbols on money and flags, and in 2004 the oak was voted the national tree by the US Congress.

Definitions of oak

1. noun

   a deciduous tree of the genus Quercus; has acorns and lobed leaves
   “great oaks grow from little acorns”

   synonyms: oak tree

   types:

   live oak

   any of several American evergreen oaks

   white oak

   any of numerous Old World and American oaks having 6 to 8 stamens in each floret, acorns that mature in one year and leaf veins that never extend beyond the margin of the leaf

   European turkey oak, Quercus cerris, turkey oak

   large deciduous tree of central and southern Europe and Asia Minor having lanceolate leaves with spiked lobes

   Quercus coccinea, scarlet oak

   medium-large deciduous tree with a thick trunk found in the eastern United States and southern Canada and having close-grained wood and deeply seven-lobed leaves turning scarlet in autumn

   Quercus ellipsoidalis, jack oak, northern pin oak

   small to medium deciduous oak of east central North America; leaves have sharply pointed lobes

   red oak

   any of numerous American oaks having 4 stamens in each floret, acorns requiring two years to mature and leaf veins usually extending beyond the leaf margin to form points or bristles

   Quercus ilex, evergreen oak, holly-leaved oak, holm oak, holm tree

   evergreen oak of southern Europe having leaves somewhat resembling those of holly; yields a hard wood

   Quercus imbricaria, laurel oak, shingle oak

   small deciduous tree of eastern and central United States having leaves that shine like laurel; wood is used in western states for shingles

   Quercus incana, bluejack oak, turkey oak

   small semi-evergreen shrubby tree of southeastern United States having hairy young branchlets and leaves narrowing to a slender bristly point

   California black oak, Quercus kelloggii

   large deciduous tree of the Pacific coast having deeply parted bristle-tipped leaves

   American turkey oak, Quercus laevis, turkey oak

   small slow-growing deciduous shrubby tree of dry sandy barrens of southeastern United States having leaves with bristle-tipped lobes resembling turkey's toes

   Quercus laurifolia, laurel oak, pin oak

   large nearly semi-evergreen oak of southeastern United States; thrives in damp soil

   Quercus lyrata, overcup oak

   medium-large deciduous timber tree of central and southern United States; acorns deeply immersed in the cup and mature in first year

   scrub oak

   any of various chiefly American small shrubby oaks often a dominant form on thin dry soils sometimes forming dense thickets

   Japanese oak, Quercus grosseserrata, Quercus mongolica

   oak with moderately light fine-grained wood; Japan

   chestnut oak

   an oak having leaves resembling those of chestnut trees

   Quercus nigra, possum oak, water oak

   relatively tall deciduous water oak of southeastern United States often cultivated as a shade tree; thrives in wet soil

   Nuttall oak, Nuttall's oak, Quercus nuttalli

   similar to the pin oak; grows in damp sites in Mississippi River basin

   Quercus palustris, pin oak, swamp oak

   fast-growing medium to large pyramidal deciduous tree of northeastern United States and southeastern Canada having deeply pinnatifid leaves that turn bright red in autumn; thrives in damp soil

   Quercus phellos, willow oak

   medium to large deciduous oak of the eastern United States having long lanceolate leaves and soft strong wood

   Quercus stellata, box white oak, brash oak, iron oak, post oak

   small deciduous tree of eastern and central United States having dark green lyrate pinnatifid leaves and tough moisture-resistant wood used especially for fence posts

   Quercus suber, cork oak

   medium-sized evergreen oak of southern Europe and northern Africa having thick corky bark that is periodically stripped to yield commercial cork

   Quercus texana, Spanish oak

   small deciduous tree having the trunk branched almost from the base with spreading branches; Texas and southern Oklahoma

   Chinese cork oak, Quercus variabilis

   medium to large deciduous tree of China, Japan, and Korea having thick corky bark

   Quercus velutina, black oak, quercitron, quercitron oak, yellow oak

   medium to large deciduous timber tree of the eastern United States and southeastern Canada having dark outer bark and yellow inner bark used for tanning; broad five-lobed leaves are bristle-tipped

   California live oak, Quercus agrifolia, coast live oak

   highly variable often shrubby evergreen oak of coastal zone of western North America having small thick usually spiny-toothed dark-green leaves

   American white oak, Quercus alba

   large slow-growing deciduous tree of the eastern United States having stout spreading branches and leaves with usually 7 rounded lobes; yields strong and durable hard wood

   Arizona white oak, Quercus arizonica

   semi-evergreen shrub or small tree of Arizona and New Mexico having acorns with hemispherical cups

   Quercus bicolor, swamp oak, swamp white oak

   large deciduous oak of the eastern United States with a flaky bark and leaves that have fewer lobes than other white oaks; yields heavy strong wood used in construction; thrives in wet soil

   Quercus chrysolepis, canyon live oak, canyon oak, iron oak, maul oak

   medium-sized evergreen of southwestern United States and northwestern Mexico with oblong leathery often spiny-edged leaves

   Quercus falcata, southern red oak, swamp red oak, turkey oak

   large round-topped deciduous tree with spreading branches having narrow falcate leaves with deeply sinuate lobes and wood similar to that of northern red oaks; New Jersey to Illinois and southward

   Garry oak, Oregon oak, Oregon white oak, Quercus garryana

   small deciduous tree of western North America with crooked branches and pale grey bark

   Quercus ilicifolia, bear oak

   shrubby oak of southeastern United States usually forming dense thickets

   California white oak, Quercus lobata, roble, valley oak, valley white oak

   tall graceful deciduous California oak having leathery leaves and slender pointed acorns

   Quercus macrocarpa, bur oak, burr oak, mossy-cup oak, mossycup oak

   medium to large deciduous oak of central and eastern North America with ovoid acorns deeply immersed in large fringed cups; yields tough close-grained wood

   Quercus marilandica, blackjack, blackjack oak, jack oak

   a common scrubby deciduous tree of central and southeastern United States having dark bark and broad three-lobed (club-shaped) leaves; tends to form dense thickets

   Quercus michauxii, swamp chestnut oak

   medium to large deciduous tree of moist areas of southeastern United States similar to the basket oak

   Quercus muehlenbergii, chinkapin oak, chinquapin oak, yellow chestnut oak

   medium-sized deciduous tree of the eastern United States that yields a strong durable wood

   Quercus myrtifolia, myrtle oak, seaside scrub oak

   small evergreen shrub or tree of southeastern United States; often forms almost impenetrable thickets in sandy coastal areas

   Quercus petraea, Quercus sessiliflora, durmast

   deciduous European oak valued for its tough elastic wood

   Quercus montana, Quercus prinus, basket oak, cow oak

   medium to large deciduous tree of the eastern United States; its durable wood is used as timber or split and woven into baskets or chair seats

   Quercus prinoides, dwarf chinkapin oak, dwarf chinquapin oak, dwarf oak

   deciduous shrubby tree of northeastern and central United States having a sweet edible nut and often forming dense thickets

   English oak, Quercus robur, common oak, pedunculate oak

   medium to large deciduous European oak having smooth leaves with rounded lobes; yields hard strong light-colored wood

   Quercus borealis, Quercus rubra, northern red oak

   large symmetrical deciduous tree with rounded crown widely distributed in eastern North America; has large leaves with triangular spiny tipped lobes and coarse-grained wood less durable than that of white oaks

   Quercus shumardii, Shumard oak, Shumard red oak

   large deciduous red oak of southern and eastern United States having large seven-lobed to nine-lobed elliptical leaves, large acorns and medium hard coarse-grained wood

   Quercus virginiana, southern live oak

   medium-sized evergreen native to eastern North America to the east coast of Mexico; often cultivated as shade tree for it wide-spreading crown; extremely hard tough durable wood once used in shipbuilding

   Quercus wislizenii, Quercus wizlizenii, interior live oak

   a small shrubby evergreen tree of western North America similar to the coast live oak but occurring chiefly in foothills of mountain ranges removed from the coast; an important part of the chaparral

   type of:

   tree

   a tall perennial woody plant having a main trunk and branches forming a distinct elevated crown; includes both gymnosperms and angiosperms
2. noun

   the hard durable wood of any oak; used especially for furniture and flooring
   types:

   fumed oak

   oak given a weathered appearance by exposure to fumes of ammonia; used for cabinetwork

   holm oak

   hard wood of the holm oak tree

   type of:

   wood

   the hard fibrous lignified substance under the bark of trees