minnow

Any of certain small fish.

The common minnow (Phoxinus phoxinus), a small freshwater fish of the carp family Cyprinidae which has a green back with black elongated blotches, commonly swimming in large shoals.

Chiefly with a qualifying word: That fish or any of a number of other (small) fish from the family Cyprinidae.

(US) Any of those fish or other small (usually freshwater) fish from other families.

(Australia, New-Zealand) Synonym of galaxiid (“any member of the family Galaxiidae of mostly small freshwater fish of the Southern Hemisphere”); specifically, the common galaxias, inanga, or jollytail (Galaxias maculatus).

(UK) Synonym of stickleback (family Gasterosteidae).

(figurative) A person or thing of relatively little consequence, importance, or value.

(figurative) a team that is considered less skilled and not expected to win many, if any, of its matches.

An artificial bait in the form of a small fish.

To fish for minnows (noun sense 1 and subsenses).

To fish, especially for trout, using minnows as bait.

(rare) Very small; tiny.