What's "wary" mean?

Native speaker’s answer
Rebecca
To be "wary" means to be "cautious" of something or someone, as there could be a possibility of danger or problems. Here, she's saying to be careful of using the correct letter case, or it might not work. Ex: Be wary of talking to strangers, kids. Ex: I'm wary of doing my essay too late because I want it to be good enough to get an A. So I'm going to start it tonight.