Love a second? You heard right! (5)
I believe the answer is:
amour
'love' is the definition.
('love' in French)
'a second? you heard right' is the wordplay.
'second?' becomes 'mo' (both are short periods of time).
'you heard' becomes 'U' (homophone of 'you').
'right' becomes 'r' (common abbreviation).
'a'+'mo'+'u'+'r'='AMOUR'
(Other definitions for amour that I've seen before include "20 [AFFAIR]" , "(Illicit) sexual relationship" , "French love affair, usually secret" , "Secretive affair" , "illicit liaison" .)