rhabdom
noun
rhab·dom ˈrab-ˌdäm 
-dəm
variants or rhabdome
ˈrab-ˌdōm
: one of the minute rodlike structures in the retinulae in the compound eyes of arthropods
Word History
Etymology
borrowed from German Rhabdom, borrowed from Late Greek rhábdōma "bundle of rods," from Greek rhábdos "rod, wand" + -ōma -ome — more at rhabdo-
First Known Use
1878, in the meaning defined above