- the production of offspring by an organism in its larval or juvenile form; the elimination of the adult phase of the life cycle.
- a slowing of the rate of development with the consequent retention in adulthood of a feature or features that appeared in an earlier phase in the life cycle of ancestral individuals: Neoteny in the ostrich has resulted in adult birds sporting the down feathers of nestlings.
- the persistence of larval or fetal features in the adult form of an animal. For example, the adult axolotl, a salamander, retains larval external gills
