1With a person or thing as subject and bare or to -infinitive. Was necessitated or obliged; should, must (with both deontic and epistemic force).
2With bare or (now usually) to -infinitive. With present or future reference. Is necessitated to; is destined to; shall.
Late Middle English (in an earlier sense). Originally a contracted variant of behoved, 3rd singular past indicative of behove; subsequently sometimes reinterpreted as a stem form showing invariant present and past forms.