must

A must is something that's so important it can't be missed or ignored. When you're taking kayaking lessons, a lifejacket is a must.

Anything that is required is a must: drinking enough water is a must for being healthy. When you adopt a new dog, making sure he'll get along with your cat is a must. Another meaning of the noun must is a stale, stuffy smell. Your damp basement and dry, hot attic might both smell of must. This meaning comes from the adjective musty, a variation on the older, now obsolete moisty.

Primary Meanings of must

1.
nadj
a necessary or essential thing
highly recommended
2.
n
the quality of smelling or tasting old or stale or mouldy
3.
n
grape juice before or during fermentation
Full Definitions of must
1

n a necessary or essential thing

“seat belts are an absolute must
Type of:
essential, necessary, necessity, requirement, requisite
anything indispensable

adj highly recommended

“a book that is must reading”
Synonyms:
essential
basic and fundamental
2

n the quality of smelling or tasting old or stale or mouldy

Synonyms:
moldiness, mustiness
Type of:
staleness
having lost purity and freshness as a consequence of aging
3

n grape juice before or during fermentation

Type of:
grape juice
the juice of grapes

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