Love the guys signal (4)
I believe the answer is:
omen
'signal' is the definition.
(omen is a kind of signal)
'love the guys' is the wordplay.
'love' becomes 'o' (In tennis, 'love' means 'zero').
'the guys' becomes 'men'.
'o'+'men'='OMEN'
(Other definitions for omen that I've seen before include "Sign of something about to happen" , "Augury, portent" , "Harbinger, augury" , "Harbinger, portent" , "Portent of evil" .)