To be fully aware or cognizant of someone or something, especially if it is suspicious, illegal, or malicious in nature or intention. We'd better watch our step—I think the police are wise to us! I'm wise to your scheme, and I'll find a way to make sure you can never put it into action! Now that I've been teaching for a few years, I'm wise to kids who try to cheat on their tests.

To become fully aware or cognizant of someone or something, especially if he, she, or it is suspicious, illegal, or malicious in nature or intention. We'd better watch our step—I think the police are getting wise to us! I hope my brother doesn't get wise to my scheme to take over the company.