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.
- To be obliged or required by morality, law, or custom: Citizens must register in order to vote.
- To be compelled, as by a physical necessity or requirement: Plants must have oxygen in order to live.
- Used to express a command or admonition: You must not go there alone. You simply must be careful.
- To be determined to; have as a fixed resolve: If you must leave, do it quietly.
- Used to indicate inevitability or certainty: We all must die.
- Used to indicate logical probability or presumptive certainty: If the lights were on, they must have been at home.
- Archaic To be required or obliged to go: "I must from hence” ( Shakespeare).
- Something that is absolutely required or indispensable: Promptness on the job is a must. Comfortable boots are a must when going on a hike.
- The quality or condition of being stale or musty.
- The unfermented or fermenting juice expressed from fruit, especially grapes.
- Variant of musth.