The guys count intellectually (8)
I believe the answer is:
mentally
'intellectually' is the definition.
(I've seen this before)
'the guys count' is the wordplay.
'the guys' becomes 'men' (guy can mean a man).
'count' becomes 'tally' (tallying is a kind of counting).
'men'+'tally'='MENTALLY'
(Other definitions for mentally that I've seen before include "not physically" , "Intellectually" , "how intelligence is developed" , "Cerebrally" , "in their heads" .)