The crossword solutions for the term BE APPROPRIATE OR NECESSARY are APT and USURP. APT is an adjective meaning suitable or appropriate for a particular person, purpose, or situation. It is derived from the Latin aptus, meaning 'fitted, adapted'. USURP is a verb meaning to seize and hold (power or rights) in one's own hands, especially without legal authority. It is derived from the Latin usurpare, meaning 'to take possession of by force'.