The story
- Middle English · inherited frommousere“a hunter of mice”
- English todaymouser
From 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.
Words from the same roots
Middle Englishmousere all →
mouse-ear
Etymology from Wiktionary, CC BY-SA 4.0.