noun
caustic words; defiant words
Almost always used in the set phrase 啖呵を切る (たんかをきる), meaning 'to speak sharply or defiantly'. The noun alone is rarely used independently.
See also: 啖呵を切る
彼は上司に啖呵を切って辞表を出した。
He spoke defiantly to his boss and handed in his resignation.
あの政治家は記者会見で啖呵を切る
That politician is famous for speaking sharply at press conferences.
毒舌 refers to a sharp or malicious tongue, often describing a person's habitual way of speaking, while 啖呵 is used almost exclusively in the phrase 啖呵を切る for a specific defiant or caustic remark.
The kanji 啖呵 are ateji (phonetic equivalents) and do not contribute meaning. The word likely derives from a mimetic or sound-symbolic origin, but the exact derivation is uncertain.