Laugh and discard love heartlessly (7)
I believe the answer is:
chuckle
'laugh' is the definition.
(I know that chuckle is a type of laugh)
'discard love heartlessly' is the wordplay.
'discard' becomes 'chuck' (chuck away).
'heartlessly' says to hollow out the word (remove centre letters).
'love' with its middle taken out is 'le'.
'chuck'+'le'='CHUCKLE'
'and' is the link.
(Other definitions for chuckle that I've seen before include "Chortle" , "A quiet or half-suppressed laugh" , "Muted laugh" , "Laugh quietly" , "Tittering laugh" .)