Couple tango with love (3)
I believe the answer is:
two
'couple' is the definition.
(two people or things)
'tango with love' is the wordplay.
'tango' becomes 'T' (phonetic alphabet: alpha, bravo, charlie etc.).
'with' becomes 'w' (abbreviation).
'love' becomes 'o' (love means zero in tennis).
't'+'w'+'o'='TWO'
(Other definitions for two that I've seen before include "'It takes ? to tango'" , "Item" , "2" , "One plus one" , "Number in pair" .)