Boyfriend gives a sign of life! (10)
I believe the answer is:
heartthrob
'boyfriend' is the definition.
(thesaurus)
'a sign of life' is the wordplay.
I cannot really understand how this works, but
'a' is within the answer.
'sign' could be 'he' (he is a kind of sign) and 'he' is found within the answer.
'of' could be 'o' and 'o' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
'gives' is the link.
Can you help me to learn more?
(Other definitions for heartthrob that I've seen before include "Object of fascination" , "Romantic and good-looking male celebrity" , "Beat" , "idol" .)