Multiplayer version of Quizl
I've not seen any multiplayer versions before, but why couldn't you play this the same way that you play multiplayer battleships?

I've played a few variations of multiplayer battleships. One where you select a square in a single opponent's grid, another where all shots hit all grids.  I've even played a version where your shots hit all opponent's grids, but not your own (which made it very tempting to shoot at your own ships).

Players would score for guessing a password as in the original game.  You could implement a score penalty for an incorrect guess, otherwise there would be significantly less benefit in revealing an opponent's square.

If you want to enlarge the search space (for example, if playing that all shots hit all grids) then each player could create several 5x5 grids, only one of which contains a five letter word.