Modified one's language (3)
I believe the answer is:
neo
'language' is the definition.
(I've seen this before)
'modified one's' is the wordplay.
'modified' indicates an anagram.
'one' is an anagram of 'NEO'.
(Other definitions for neo that I've seen before include "Hero of The Matrix films; new (prefix)" , "Prefix meaning new or recent" , "Prefix meaning new - try one" , "New (suffix)" , "Prefix meaning new of modern form of" .)