must

{{11}}must (n.¹) "new wine," O.E. must, from L. mustum (also source of O.H.G., Ger. most, O.Fr. moust, Mod.Fr. moût, Sp., It. mosto), short for vinum mustum "fresh wine," neuter of mustus "fresh, new, newborn," perhaps lit. "wet," and from PIE *mus-to-, from root *meus- "damp" (see MOSS (Cf. moss)).

{{12}}must (n.²) "mold," c.1600, perhaps a back-formation of MUSTY (Cf. musty) (q.v.).

{{12}}must (n.³) "male elephant frenzy," 1871, from Urdu mast "intoxicated, in rut," from Pers. mast, lit. "intoxicated," related to Skt. matta- "drunk, intoxicated," pp. of madati "boils, bubbles, gets drunk," from PIE root *mad- "wet, moist" (see MAST (Cf. mast) (n.²)).

{{13}}must (n.⁴) "that which has to be done, seen, or experienced," 1892, from MUST (Cf. must) (v.). As an adjective, "obligatory, indispensable," by 1912, from the noun; must-read is from 1959.

{{14}}must (v.) O.E. moste, past tense of motan "have to, be able to," from P.Gmc. *mot- "ability, leisure (to do something)" (Cf. O.S. motan "to be obliged to, have to," O.Fris. mota, M.L.G. moten, Du. moeten, Ger. müssen "to be obliged to," Goth. gamotan "to have room to, to be able to"), perhaps from PIE root *med- "to measure, to take appropriate measures" (see MEDICAL (Cf. medical) (adj.)). Used as present tense from c.1300, from the custom of using past subjunctive as a moderate or polite form of the present.