"Not with it" is a colloquial phrase used to describe someone who is out of touch, confused, or generally unaware of what's happening around them. Sometimes the phrase can be seen as being disrespectful or dismissive, so there are several alternative synonyms that can be used in its place. One option is "zoned out," which suggests that someone is preoccupied or distracted. Another option is "clueless," which implies a lack of knowledge or understanding. A third possibility is "out of the loop," which conveys a sense of being excluded or left behind. Ultimately, the choice of synonym will depend on the context and the tone that is desired.