"Be leery of" is a phrase that means to be cautious, suspicious or hesitant of someone or something. There are several similar phrases that can be used interchangeably with it like "be wary of", "be apprehensive of", "be distrustful of", "be mistrustful of", or "be skeptical of". These phrases indicate that the speaker is hesitant to trust or believe in something without further proof or evidence because there is some level of doubt or uncertainty involved. By using these synonyms, one can express their apprehension in a more nuanced and varied way, adding a layer of depth and precision to their language.