Runs external computer device (6)
I believe the answer is:
router
'computer device' is the definition.
(device in a computer network)
'runs external' is the wordplay.
'runs' becomes 'r' (cricket abbreviation).
'external' becomes 'outer' (similar in meaning).
'r'+'outer'='ROUTER'
(Other definitions for router that I've seen before include "device fitted to computer" , "that easily beats the competition" , "Carpentry power tool" , "Device that forwards data between computer networks" , "Computer equipment" .)