Cryptomorphic is a word that refers to something that has a hidden or secret form. There are several synonyms that can be used in place of cryptomorphic depending on the context of its usage. The word enigmatic conveys the sense of mysteriousness and puzzlement that sometimes accompanies cryptomorphic. Arcane is another synonym that refers to something that is obscure or difficult to understand, often due to its complexity. Esoteric, on the other hand, implies a high level of specialized knowledge that is only understood by a select few. Other possible synonyms for cryptomorphic include cryptic, surreptitious, enigmatic, and murky, among others.