Obligate vs. Obliged — What's the Difference?

As an adjective, obligate means "by necessity" (antonym facultative) and is used mainly in biology in phrases such as: Obligate aerobe, an organism that cannot survive without oxygen Obligate anaerobe, an organism that cannot survive in the presence of oxygen Obligate air-breather, a term used in fish physiology to describe those that respire entirely from the atmosphere Obligate biped, Bipedalism designed to walk on two legs Obligate carnivore, an organism dependent for survival on a diet of animal flesh. Obligate hibernation, a state of inactivity in which some organisms survive conditions of insufficiently available resources.

To compel or require (someone) to do something, as by circumstance or legality

To compel or constrain by a social, legal, or moral requirement.

To make indebted or grateful

To cause to be grateful or indebted; oblige

To do a service or favor for

To commit (money, for example) in order to fulfill an obligation.

To do a service or favor

Able to exist or survive only in a particular environment or by assuming a particular role

Under an obligation to do something.

An obligate organism.

Grateful or indebted because of a favor done.

To bind, compel, constrain, or oblige by a social, legal, or moral tie.

Simple past tense and past participle of oblige

To cause to be grateful or indebted; to oblige.

Under a moral obligation to do something

To commit (money, for example) in order to fulfill an obligation.

(biology) Requiring a (specified) way of life, habitat, etc..

Indispensable; essential; necessary; obligatory; mandatory; unavoidably invoked.

To bring or place under obligation, moral or legal; to hold by a constraining motive.

To bind or firmly hold to an act; to compel; to constrain; to bind to any act of duty or courtesy by a formal pledge.

Force or compel somebody to do something;

Commit in order to fulfill an obligation;

Bind by an obligation; cause to be indebted;

Restricted to a particular condition of life;