He muttered a complaint about his work.
I couldn't catch his murmur.
I heard a mutter of discontent.
His tweet became a hot topic.
I found an interesting tweet.
She posts a short tweet every day.
A faint murmur could be heard from the next room.
Usually written in kana; the kanji form 呟き is rare.
Kanji form is uncommon; learners should use the kana spelling.
Noun form of the verb つぶやく (to murmur). The verb itself is of native Japanese origin, likely onomatopoeic, related to the sound of muttering.