Other forms: laciest; lacily; lacier
Lacy means gauzy and delicate, with small, ornate details. Think of your grandma's lacy kitchen curtains or the lacy fronds of a fern.
This adjective means "like lace," that gauzy fabric that's patterned with tiny holes. You might decorate a table with lacy doilies or a lacy tablecloth, wear a long skirt with a lacy flounce at the bottom, or tidy the lacy throw pillows on a couch. This type of delicate pattern in nature is also lacy: "I love looking at the sun filtering through the lacy leaves of the big oak tree."