—adj.ob'li-git, -gāt"), [key]
—v. -gat•ed, -gat•ing,
1. to bind or oblige morally or legally: to obligate oneself to purchase a building.
2. to pledge, commit, or bind (funds, property, etc.) to meet an obligation.
1. morally or legally bound; obliged; constrained.
2. necessary; essential.
3. Biol.restricted to a particular condition of life, as certain organisms that can survive only in the absence of oxygen: obligate anaerobe (opposed to facultative).
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.