show white feather
a symbol of cowardice.
show the white feather,
to behave in a cowardly manner.
orig. from a white feather in a gamecock's tail, taken as a sign of inferior breeding and hence of poor fighting qualities
a symbol or mark of cowardice
show the white feather
to act in a cowardly manner
[from the belief that a white feather in a gamecock's tail was a sign of a poor fighter]
Collins English Dictionary - Complete & Unabridged 10th Edition
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