There are a variety of synonyms that can be used to describe someone who is socially incompatible. One such term might be "misfit," which implies that someone doesn't quite fit in with the social norms of a group or community. Another possible synonym is "outcast," which can suggest a more extreme sense of social isolation or ostracism. Other synonyms might include "awkward," "unapproachable," "unfriendly," "antisocial," or "isolated." Each of these terms captures a slightly different aspect of someone who struggles to connect with others on a social level, and can be used to convey a range of emotions and perspectives about this type of person.