When it comes to expressing an incomplete understanding of something, there are several synonyms for the phrase "not comprehensively." One alternative could be "partially," indicating that the understanding is limited in some way. Another option is "incompletely," which suggests that there are missing pieces to the puzzle. "Fragmentarily" is another possible synonym, expressing the idea that there are only pieces of the whole picture available. "Imperfectly" could also work, suggesting that there are flaws or gaps in the understanding. Finally, "superficially" could imply that there has been a cursory examination of the matter, without a deep dive into all the details.