obligated

Concise Oxford English Dictionary © 2008 Oxford University Press:
obligate/ˈɒblɪɡeɪt/

▶verb

• 1 compel (someone) to undertake a legal or moral duty.

• 2 US commit (assets) as security.

▶adjective Biology restricted to a particular function or mode of life: an obligate parasite.

– derivatives
obligator noun.

– origin ME (as adj. in the sense ‘bound by the law’): from L. obligat-, obligare (see oblige).