Coelenterate and Medusa

Coelenterate noun - Radially symmetrical animals having saclike bodies with only one opening and tentacles with stinging structures; they occur in polyp and medusa forms.

Medusa and coelenterate are semantically related. In some cases you can replace term "Medusa" with "Coelenterate", this nouns are similar.

Medusa noun - One of two forms that coelenterates take: it is the free-swimming sexual phase in the life cycle of a coelenterate; in this phase it has a gelatinous umbrella-shaped body and tentacles.

Coelenterate and medusa are semantically related. Sometimes you can use "Coelenterate" instead a noun "Medusa".