expression, i-adjective
neither fish nor fowl; hard to predict; up in the air; unclear
Idiomatic expression used when the nature, outcome, or identity of something is completely uncertain and cannot be guessed. Often applied to people, situations, or future prospects.
彼はまだ新人で、海のものとも山のものともつかない存在だ。
He's still a newcomer, a person who is neither fish nor fowl.
この計画が成功するかどうか、今は海のものとも山のものともつかない。
Whether this plan will succeed is still up in the air.