Word Origin & History
pet"peevishness, offense at feeling slighted," 1590, in phrase take the pet "take offense." Perhaps from pet (1) on a similar notion to that in Amer.Eng. that gets my goat, but the underlying notion is obscure, and the form of the original expression makes this doubtful. This word seems to have been originally
EXPANDa southern Eng. term, while pet (1) was Scottish.
COLLAPSE