kvetch

• n. (米国) 過失を指摘する人。
• vi.（米）定期的に愚痴をこぼす。

イディッシュ語のkvetch、中高地ドイツ語のquetschen「つぶす」から。complain（不平を言う）、whine（泣き言）が語源。

kvetch (v.)

"to complain, whine," 1953 (implied in kvetching), from Yiddish kvetshn, literally "squeeze, press," from German quetsche "crusher, presser." As a noun, from 1936 as a term of abuse for a person.