also: ききすてならない
inexcusable; unpardonable; can't be ignored
Used when something said is so offensive or unacceptable that one cannot let it pass without comment. Often follows a statement that the speaker finds outrageous.
His rude remark is inexcusable; I can't let it pass.
That joke is unpardonable; I can't just ignore it.
Standard kanji spelling. The reading ききずてならない is more common than ききすてならない.
Alternate reading; less common but still encountered.
From 聞き (hearing) + 捨て (throwing away, discarding) + ならない (cannot be). Literally 'cannot be heard and thrown away', i.e., cannot be ignored.