cantharis
noun
can·tha·ris ˈkan(t)-thə-rəs 
plural cantharides kan-ˈther-ə-ˌdēz
-ˈtha-rə-
1
: spanish fly sense 1
2
cantharides plural in form but singular or plural in construction : a preparation of dried beetles (such as Spanish flies) used in medicine as a counterirritant and formerly as an aphrodisiac
Word History
Etymology
Middle English cantaride (usually in plural) "the blister beetle Lytta vesicatoria (earlier Cantharis vesictoria), preparation made from the beetles," borrowed from Latin cantharid-, cantharis (plural cantharidēs) "the beetle Lytta vesicatoria," borrowed from Greek kantharís, from kántharos "the dung beetle Gymnopleurus mopsus" (of obscure origin) + -id-, -is, diminutive suffix
Note: The Greek word kántharos denotes various things (beetle, cup, a kind of boat, a species of fish) the interrelations of which are far from clear; possibly several words of distinct origin have merged.
First Known Use
14th century, in the meaning defined at sense 1
Medical Definition
cantharis 1 of 2
noun
can·tha·ris ˈkan(t)-thə-rəs
plural cantharides kan-ˈthar-ə-ˌdēz
1
: spanish fly sense 1
2
cantharides plural in form but singular or plural in construction : a preparation of dried beetles and especially Spanish flies that contains cantharidin and is used in medicine as a blister-producing agent and formerly as an aphrodisiac
called also Spanish fly
Cantharis
2 of 2noun
Can·tha·ris ˈkan(t)-thə-rəs
taxonomic synonym of lytta