noun. An insult applicable to those--including but not limited to penguins--with a certain pear-shaped posterior.
Related terms: assbutt, lardbutt, blubberbutt, bubblebutt, puckerbutt, wafflebutt, butthead, buttbreath, butthole, buttmunch, buttwipe.
Real citation: "Lonely women waiting...a recharged bachelorhood...and a stable hairline at fifty! I'm back, pearbutt!"
(Steve Dallas, Opus, Dec. 5, 2004)
Made-up citation: "What will it take to turn my pearbutt into an ass o' steel?"