Prefix meaning "modern" (3)
I believe the answer is:
neo
'prefix meaning modern' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for neo that I've seen before include "Prefix meaning new or recent" , "Prefix meaning new, maybe one" , "New (suffix)" , "Hero of The Matrix films; new (prefix)" , "Prefix donating new" .)