must 1
/must/ , auxiliary verb.
1. to be obliged or bound to by an imperative requirement: I must keep my word.
2. to be under the necessity to; need to: Animals must eat to live.
3. to be required or compelled to, as by the use or threat of force: You must obey the law.
4. to be compelled to in order to fulfill some need or achieve an aim: We must hurry if we're to arrive on time.
5. to be forced to, as by convention or the requirements of honesty: I must say, that is a lovely hat.
6. to be or feel urged to; ought to: I must buy that book.
7. to be reasonably expected to; is bound to: It must have stopped raining by now. She must be at least 60.
8. to be inevitably certain to; be compelled by nature: Everyone must die.
v.i.
9. to be obliged; be compelled: Do I have to go? I must, I suppose.
10. Archaic. (sometimes used with ellipsis of go, get, or some similar verb readily understood from the context): We must away.
adj.
11. necessary; vital: A raincoat is must clothing in this area.
n.
12. something necessary, vital, or required: This law is a must.
[ bef. 900; ME most ( e ), OE moste (past tense); c. G musste. See MOTE 2 ]
Syn. 1. MUST, OUGHT, SHOULD express necessity or duty. MUST expresses necessity or compulsion: I must attend to those patients first. Soldiers must obey orders. OUGHT (weaker than MUST) expresses obligation, duty, desirability: You ought to tell your mother. SHOULD expresses obligation, expectation, or probability: You are not behaving as you should. Children should be taught to speak the truth. They should arrive at one o'clock.
must 2
/must/ , n.
new wine; the unfermented juice as pressed from the grape or other fruit.
[ bef. 900; ME, OE mustum, short for vinum mustum new wine ]
must 3
/must/ , n.
mold; moldiness; mustiness: a castle harboring the must of centuries.
[ 1595-1605; back formation from MUSTY 1 ]
must 4
/must/ , n.
musth.
must 5
/must/ , Obs.
n.
1. musk, esp. a powder made from musk.
v.t.
2. to powder (the hair).
[ 1480-90; earlier moist must, var. of musc MUSK ]