The phrase "let have it" can have different meanings depending on the context. However, its antonyms typically imply stopping or withholding something. One antonym for "let have it" could be "prevent," which means to hinder or restrain something from happening, or to stop someone from doing something. Another antonym could be "deny," which means to refuse, prohibit or withhold something from someone. Additionally, "restrain" or "stop" could be considered antonyms for "let have it" depending on the context. Overall, the antonyms for "let have it" convey a sense of control or withholding rather than an allowance or permission.