The article considers the morphological and functional characteristics of some objects of parasitology, the etymology of names and the methods of their nomination. Knowledge of the history of origin, the realization of the word-building analysis of parasite names and understanding the semantic components of terms will help to make the educational process more interesting and more effective. The names of parasites are divided into several groups: the names, in which there are semantic elements, which indicate the names of diseases; the names, comprising the semantic elements of anatomical nature; the names, comprising the semantic elements of geographical nature; the names, indicating the connection of term with the history of its detection and containing surnames of researchers; the names, containing semantic elements, which characterize the exterior view of parasites. Besides, the article shows the connection of semantic association (metaphorical transfer) between the initial meaning of the term in the language — ultimate source (Latin or Greek) with the morphological and functional characteristics of various parasites.