6 letters · 8 points in Scrabble
noun a cat proficient at mousing
originFrom Middle English mousere (“a hunter of mice”), equivalent to mouse + -er (agent noun suffix) or + -er (occupational suffix). The “moustache” sense is apparently an extended usage (i.e., a cat’s whiskers, jocularly transferred to human beings), possibly with influence from moustache.
Etymology from Wiktionary, CC BY-SA 3.0