Definition of "squealer"

Any animal or person who squeals.  examples

A pig.  examples

(slang) An informant.

(informal, Canada, US, Australia) A kind of jug used to carry beer having 1 litre or 32 ounce capacity (half the size of a growler).  examples

Anything that makes a squealing noise.  examples

The European swift.  examples

The harlequin duck.  examples

The American golden plover.  examples

A young pigeon.  examples