akushu

Bad move (J. akushu　悪手) describes, well, a bad move. Interestingly, though, a move can be reasonable when played but become a bad move later (J. akushu ni naru). A pro might use as a reason for rejecting a particular move the fact that it has this kind of potential for becoming (or being made into) a bad move.

Bob McGuigan: This "good move" becoming "bad move" phenomenon often happens due to a later mistake. For example a strategy might be rejected or labelled a mistake because it makes an earlier move into a bad move. Or a move might be rejected because later a necessary move could make it into a bad move, I suppose.