Meaning

adjective quiet and timid and ineffectual

adjective infested with mice

adjective of something having a drab pale brown color resembling a mouse

originEtymology tree Proto-Indo-European *múHs Proto-Germanic *mūs Proto-West Germanic *mūs Old English mūs Middle English mous English mouse Proto-Indo-European *-kos Proto-Germanic *-gaz Proto-West Germanic *-g Old English -iġ Middle English -y English -y English mousy From mouse + -y (forms adjectives from nouns).

Etymology from Wiktionary, CC BY-SA 3.0