The phrase "mess with" is a colloquial expression that means to interfere with someone or something in a malicious or playful way. There are various synonyms for this phrase based on the context of the sentence. Some common synonyms for "mess with" include "play with," "manipulate," "bother," "trifle with," "tamper with," "meddle," and "disturb." "Play with" is a softer synonym that conveys a non-threatening tone, while "manipulate" is a more severe synonym that implies an intention to control or deceive. "Bother," "trifle with," and "disturb" are synonyms that suggest a degree of annoyance or agitation, while "tamper with" and "meddle" express a more serious level of intrusion or disruption.