must (1)

i. [A defective verb used as an auxiliary. The infinitive mote is obsolete, and the Mid. Eng. moste, moot, mot, are also lost. The A. S. inf in itive mot an is not found; the pr. t. is ic mót I am able, I may, I can, pt. t. ic moste; cogn. with O. S. mótan, pr. t. ik mót, ik muot, pt. t. ik mósta; O. Fris. pr. t. ik mot, pt. t. ik moste; Dut. moeten =to be obliged, pr. t. ik moet, pt. t. ik moest; Sw. måste I must; Ger. mü en, pr. t. ich mu , pa. t. ich mu te; M. H. Ger. muezen; O. H. Ger. mózan: Goth. pr. t. ik mot, pt. t. ik most a.] 1. To be bound; to be obliged; to be under a nece ity either physically or morally to do or suffer something. "We must be free or die, who speak the tongue That Shakespeare spake." Words worth: Sonnet to Liberty. 2. To be under a logical nece ity. "Then must the love be great 'twixt thee and me, Because thou lovest the one and I the other." Shakesp.: Pa ionate Pilgrim , 105. 3. Used colloquially to expre the firm belief or conviction of the speaker; as, Hemust have lost his way, otherwise he would be here. *4. Formerly must was used absolutely with such verbs as go , get , omitted. "I must to bed."- Shakesp .: Henry VIII ., iv. 2. must (2), v . t . & i . [Prob. from must (1), s., or musty.] 2796