n.
Pronunciation: m ə s(t), ' m ə st
Function: verb
Inflected Form: present & past all persons must
Etymology: Middle English moste, from Old English m ō ste, past indicative & subjunctive of m ō tan to be allowed to, have to; akin to Old High German muozan to be allowed to, have to
Date: before 12th century
verbal auxiliary
1 a : be commanded or requested to <you must stop> b : be urged to : ought by all means to <you must read that book>
2 : be compelled by physical necessity to <one must eat to live> : be required by immediate or future need or purpose to <we must hurry to catch the bus>
3 a : be obliged to : be compelled by social considerations to <I must say you're looking well> b : be required by law, custom, or moral conscience to <we must obey the rules> c : be determined to <if you must go at least wait for me> d : be unreasonably or perversely compelled to <why must you argue>
4 : be logically inferred or supposed to <it must be time>
5 : be compelled by fate or by natural law to <what must be will be>
6 : was or were presumably certain to : was or were bound to <if he did it she must have known>
7 dialect : MAY , SHALL ― used chiefly in questions
intransitive verb archaic : to be obliged to go <I must to Coventry ― Shakespeare>