Love to be Popeye's girl (5)
I believe the answer is:
olive
'popeye's girl' is the definition.
(I've seen this in another clue)
'love to be' is the wordplay.
'love' becomes 'o' (love means zero in tennis).
'to be' becomes 'live' (to be is to live or exist).
'o'+'live'='OLIVE'
(Other definitions for olive that I've seen before include "Oil-yielding fruit" , "Greyish-green colour" , "It's branch is a symbol of peace" , "One's stoned" , "Yellow-green colour like Mediterranean fruit" .)