Other forms: hallowed; hallows; hallowing
To hallow is to bless, consecrate, or render holy by means of religious rites, especially significant religious places or the relics of saints.
As a noun, hallow means "saint." The word for our popular holiday Halloween is a shortened form of "All Hallows' Eve," or "All Saints' Eve," which precedes All Saints' Day. In the verb form, the synonyms bless and sanctify are more commonly used these days, but hallow still appears in such phrases as "hallowed ground" (ground that's been blessed) and the Christian "hallowed be Thy name" (a phrase from "The Lord's Prayer," where hallowed means "revered").