Arbovirus

Etymology
Arbovirus:

ar: from "ARthropod"

bo: from "BOrne" (meaning "carried by")

virus: "poisonous secretion" (from latin vīrus, meaning "venom" or "poisonous secretion")

Explanation
Arboviruses are viruses which enter into the human host transcutaneously, after the human is bitten by an arthropod (ar), since the virus is carried in the saliva of, and therefore borne (bo) by, that arthropod (e.g. mosquito). Viruses, being so small, might have been thought of before they were discovered, to be poisonous secretions (virus) of unknown origin, hence their name.

Synonyms
Arborvirus