hectocotylus

 
Pronunciation: /ˌhɛktə(ʊ)ˈkɒtɪləs/

noun (plural hectocotyli /-lʌɪ, -liː/)

Zoology
  • a modified arm used by male octopuses and some other cephalopods to transfer sperm to the female.

Origin:

mid 19th century: modern Latin, from hecto- 'hundred' + Greek kotulē 'hollow thing', a name given by Cuvier to what he mistakenly took to be a genus of parasitic worms