These verbs mean to cause a person or thing to follow a prescribed or dictated course. Force, the most general, usually implies the exertion of physical power or the operation of circumstances that permit no options: Tear gas forced the fugitives out of their hiding place.Compel applies especially to an act dictated by one in authority: Say nothing unless you're compelled to.Coerce invariably implies the use of strength or harsh measures in securing compliance: “The man of genius rules . . . by persuading an efficient minority to coerce an indifferent and self-indulgent majority” (James Fitzjames Stephen). Constrain suggests that one is bound to a course of action by physical or moral means or by the operation of compelling circumstances: “I will never be by violence constrained to do anything” (Elizabeth I). Oblige implies the operation of authority, necessity, or moral or ethical considerations: “Work consists of whatever a body is obliged to do” (Mark Twain). Obligate applies when compliance is enforced by a legal contract or by the dictates of one's conscience or sense of propriety: I am obligated to repay the loan.