Engage in superficially is a phrase that means to take part in something on the surface level without delving deep. The synonym for this phrase can be to dabble, toy with, or flirt. These words indicate that the engagement is not serious and lacks commitment. Another synonym for this phrase is to skim, which means to read or look at something quickly without deep understanding. Additionally, one could use the phrase "tinker with" to convey that the engagement is more of an experiment and the person is testing the waters. Overall, these synonyms convey the idea that the engagement is not significant, and the person is not fully committed.