aculeus
noun
acu·le·us
ə-ˈkyü-lē-əs
plural aculei
ə-ˈkyü-lē-ˌī
zoology
: a sharp-pointed process
specifically : an insect's ovipositor especially when modified into a sting
Word History
Etymology
borrowed from New Latin, going back to Latin, "stinger, spine (of a fish), sharp point, barb," from acū-, stem of acus "needle" + -leus, noun suffix (perhaps originally diminutive)
First Known Use
1702, in the meaning defined above