The definition of a sobriquet is an affectionate nickname.
(noun)An example of a sobriquet is a grandfather calling his grandson "pumpkin."
See sobriquet in Webster's New World College Dictionary
noun
Origin: Fr < MFr soubriquet, chuck under the chin < ?
See sobriquet in American Heritage Dictionary 4
noun
Origin:
Origin: French
Origin: , from Old French soubriquet, chuck under the chin
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