also: こしょこしょばなし
noun
whispered conversation; whispering
Refers to a conversation held in a low, secretive voice, often implying the speakers don't want to be overheard. The mimetic element こそこそ suggests furtiveness.
隣の席でこそこそ話をしている。
They are having a whispered conversation at the next seat.
会議中にこそこそ話をするのは失礼だ。
It's rude to whisper during a meeting.
ひそひそ話 also means a whispered conversation, but ひそひそ emphasizes a softer, more secretive hush, while こそこそ can imply sneaky or furtive behavior.
Compound of the mimetic adverb こそこそ (furtively, secretly) and 話 (talk, story). The mimetic root is sound-symbolic, imitating hushed, rustling sounds.