mutter (v.)youdaoicibaDictYouDict[mutter 词源字典]
early 14c., moteren "to mumble," from a common PIE imitative *mut- "to grunt, mutter" (cognates: Old Norse muðla "to murmur," Latin muttire "to mutter," Old High German mutilon "to murmur, mutter; to drizzle"), with frequentative suffix -er. Related: Muttered; muttering.[mutter etymology, mutter origin, 英语词源]
mutter (n.)youdaoicibaDictYouDict
1630s, from mutter (v.).