Catch sight of man on call (6)
I believe the answer is:
descry
'catch sight of' is the definition.
(descrying is a kind of catching sight of)
'man on call' is the wordplay.
'man' becomes 'des'.
'on' means one lot of letters go next to another.
'call' becomes 'cry' ('cry' can be a synonym of 'call').
'des'+'cry'='DESCRY'
(Other definitions for descry that I've seen before include "Perceive - make out" , "See" , "Catch sight of (poetic)" .)