Dissatisfaction with

()()わない means that someone or something rubs you the wrong way. It expresses personal dislike, irritation, or dissatisfaction.

Literal Meaning

The literal translation is something like “not eaten by the spirit” or “not to one’s taste”.

Usage Notes

気に食わない is more pointed than simply saying you do not like something. It says that a person, decision, or situation offends your preferences or expectations. ()わない comes from ()う “to eat”, but here the expression works like the English “not to one’s taste”. It contrasts with ()()る, “to like” or “to be pleased with”.

The idiom normally appears in the negative. It is rougher than ()()らない and can sound openly hostile.

Because the judgment is personal and blunt, use it carefully when speaking about someone directly.

Dictionary Definition

不満(ふまん)である。()にいらない。

To be dissatisfied. To not like.

Goo Dictionary

Further Reading

Examples

Getting on one's nerves with 気に食わない

Learn the meaning and usage of the idiom 気に食わない in Japanese, with examples from manga.
レンタルおにいちゃん » Volume 2 » Page 28

Following the death of their parents, Kanami’s big brother Kazutaka became secluded and abusive. Kanami begins to spend time with Makoto, a “rental big brother” whose advice gives her hope in restoring her brother’s former kindness. Kazutaka rebukes her attempts, suggesting that Makoto’s filling her with nonsense ideas.

一敬(かずたか):
()()わないんだよ」
“He gets on my nerves.”
適当(てきとう)(あま)言葉(ことば)(かね)()(つづ)けるような(やつ)
“He's the kind of guy who keeps taking (rental) money while spouting alluring words.”