A person you recognize by face; an acquaintance you know casually but not closely.
隣のアパートの人とは顔見知りだが、あまり話さない。
I'm acquainted with the person in the next apartment, but we don't talk much.
飲み会で顔見知りに偶然会った。
I ran into an acquaintance at the drinking party.
顔見知り程度の関係なら、深い相談はしないほうがいい。
If someone is only a casual acquaintance, it's better not to discuss deep personal matters.