Metagenetic is a rare term, and few synonyms exist for it. One possible alternative is "metagogical," which refers to the process of leading or guiding one beyond present knowledge. "Holometabolic" is another term that shares some similarities with metagenetic, as it describes the complete transformation of an organism from one life stage to the next. "Polymorphic" is yet another option, as it characterizes organisms that display multiple distinct forms or colors. "Heterochronic" could also be used, as it refers to changes in the timing or sequence of life cycle events. Overall, while few true synonyms for metagenetic exist, there are several similar terms that could be used in its place.