dunno (v.)youdaoicibaDictYouDict[dunno 词源字典]
colloquial for "(I) don't know," first attested 1842 in American English.[dunno etymology, dunno origin, 英语词源]
dunnyyoudaoicibaDictYouDict
"An underground passage or cellar, especially in a tenement", Early 19th century (in the sense 'dung'): from dialect dunnekin 'privy', probably from dung + archaic slang ken 'house'. sense 1 is perhaps a different word.