noun
A casual, often muttered complaint or grumble, typically about minor daily annoyances. Derived from the verb ぼやく.
See also: ぼやく
彼のぼやきはいつも同じだ。
His complaints are always the same.
仕事の後で、同僚とぼやきを言い合った。
After work, I exchanged grumbles with my colleague.
Noun form of the verb ぼやく (to grumble), which is likely of mimetic origin, imitating the sound of muttering.