Must

Part of speech: noun (n.)

1. The expressed juice of the grape, or other fruit, before fermentation. "These men ben full of must." Wyclif (Acts ii. 13. ). No fermenting must fills ... the deep vats. Longfellow.

2. Mustiness.

Part of speech: verb (v.)

1. To be obliged; to be necessitated; -- expressing either physical or moral necessity; as, a man must eat for nourishment; we must submit to the laws.

2. To be morally required; to be necessary or essential to a certain quality, character, end, or result; as, he must reconsider the matter; he must have been insane. Likewise must the deacons be grave. 1 Tim. iii. 8. Morover, he [a bishop] must have a good report of them which are without. 1 Tim. iii. 7.

Part of speech: verb (v.)

To make musty; to become musty.