expression, i-adjective
Internet slang; a jocular, intentionally incorrect negative form of いい (good). Used playfully to say something is not good or bad, often in casual online contexts.
See also: いい
そのアイデア、イクナイと思う。
I think that idea is not good.
今日の天気、イクナイね。
The weather today is bad, huh.