Obligate

to bind or oblige morally or legally

to obligate oneself to purchase a building.

to pledge, commit, or bind (funds, property, etc.) to meet an obligation.

morally or legally bound; obliged; constrained.

necessary; essential.

Biology . restricted to a particular condition of life, as certain organisms that can survive only in the absence of oxygen

obligate anaerobe opposed to facultative

verb

let off

verb

astrict , bind , constrain , force , indebt , make indebted , oblige , restrain , restrict , charge , pledge , coerce , compel , make , pressure