noun, plural: intermediate hosts
(parasitology) The host harbouring a parasite that primarily grows but not to the point of reaching (sexual) maturity
An intermediate host often acts as vector of parasite to reach its definitive host (where it will become mature). Thus, the intermediate host serves only as a site wherein the parasite spends a particular developmental stage of its life cycle (i.e. larval stage).
For example, some tapeworms make use of cows, pigs, and fish as intermediate hosts. When any of these animals ingests a tapeworm egg, the egg hatches and the larva moves from the intestine to the muscle of the animal where it forms a cyst. Human ingesting a partially cooked or raw meat containing the cyst may eventually harbour the parasite when the larva moves out of the cyst and grows into its mature or reproductive form and begin to reproduce inside the definitive human host.