To sulk is to be aloof or withdrawn or to show signs of being in a bad temper.(verb)
When you sit around pouting after you have lost a game, this is an example of to sulk.
See sulk in Webster's New World College Dictionary
Origin: back-form. < sulky
See sulk in American Heritage Dictionary 4
intransitive verb sulked, sulk·ing, sulks
Origin: Back-formation from sulky1.
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