The word "if it's cool" doesn't necessarily have an antonym as it refers to a subjective condition. However, if we consider the word "uncool" as its opposite, we can say that it means something is not fashionable, desirable, or popular. Therefore, the antonym for "if it's cool" could be "if it's uncool." It implies that something is not trendy, hip, or in vogue, which might affect its acceptance and popularity. In conclusion, while "if it's cool" has a positive connotation, "if it's uncool" carries a negative meaning and implies that something is not acceptable or desirable.
