Yes, that's along the lines of how I meant the word cheat.

I wouldn't specifically use either of those words because they both in my mind imply a fairly concrete victim, where here the victim is more nebulous. The journal is unlikely to be directly paying you for the review, so you aren't exactly "defrauding" them. You are likely being indirectly paid by being employed as a professor (or similar) by an institution that expects you to do things like review journal articles... which is likely the source of the motivation for being dishonest. But I don't have to specify motivation for doing the bad thing to say "that's a bad thing". "Cheat" manages to convey that it's a bad thing without being overly specific about the motivation.

I don't have a problem with a journal accepting AI assisted reviews, but when you submit a review to the journal you are submitting that you've reviewed it as per your agreement with the journal. When that agreement says "don't use AI", and you did use AI, you cheated.