Runs, wearing Edward's anorak (4)
I believe the answer is:
nerd
'anorak' is the definition.
(I've seen this before)
'runs wearing edward's' is the wordplay.
'runs' becomes 'r' (cricket abbreviation).
'wearing' is an insertion indicator.
'edward' becomes 'ned'.
'r' going into 'ned' is 'NERD'.
(Other definitions for nerd that I've seen before include "Studious bore" , "Boringly studious person" , "Boring person" , "Someone boring (about computers?)" , "Intelligent but single-minded expert" .)