[n4r9]

Yeah, in fact we tend to play without a limit on the number of guesses, just to avoid this sort of loophole. In variants like Codenames Duet I think there's also no limit on the number of guesses.

Another thing the guessers can do if unsure about one of the tiles from the last round, is to tell the clue giver which tile they think it was. The clue giver then tries to give a clue that either tenuously links to it or clearly excludes it. That can give the clue more scope for linking to several other words. It risks giving information to the other team though so is more of an final turn play.