Pedomorphic

Part of speech: adjective

Pronunciation: /pɛdəˈmɔɹfɪk/

Definitions

1. Displaying or characterized by the retention of immature physical traits in adult forms through either developmental delay or evolutionary selection
2. Showing persistent juvenile morphological features in mature organisms as a result of neoteny or arrested development
3. Having adult forms that maintain characteristics typical of juvenile stages due to slowed or altered growth patterns

Etymology: "Pedomorphic" is built from two parts that come straight from ancient Greek. The first, "pedo-", comes from "pais" (genitive "paidos"), meaning "child," which also gave English words such as "pediatrics" and "pedagogue." The second, "-morphic," comes from "morphē," meaning "form" or "shape," the root behind "amorphous" and "metamorphosis." Put together, the term literally means "child-shaped." The word is a technical coinage from modern biology rather than a term that existed in antiquity. Biologists use it to describe adult organisms that keep juvenile features, such as a human skull shape that stays rounded and small-jawed, or an axolotl that remains aquatic with gills instead of metamorphosing into a land-dwelling salamander. The idea behind the word is that the adult still looks like its own young, whether the cause is slowed development or natural selection favoring the youthful form.