i-adjective
nagging; critical; fault-finding
Describes a person who frequently complains, criticizes, or finds fault with others, often in an annoying way.
彼は口やかましい上司で、いつも細かいことを指摘する。
He is a nagging boss who always points out small things.
口やかましい姑に悩まされている。
I'm troubled by my critical mother-in-law.
i-adjective
talkative; gossipy; chatty
Used for someone who talks a lot, often about others' affairs, sometimes with a negative connotation of being gossipy.
隣の奥さんは口やかましくて、近所の噂話ばかりしている。
The neighbor's wife is talkative and always gossiping about the neighborhood.