Foolhardy, heartless and hollow (6)
I believe the answer is:
recess
'hollow' is the definition.
(thesaurus)
'foolhardy heartless' is the wordplay.
'foolhardy' becomes 'reckless' (synonyms).
'heartless' says to hollow out the word (remove centre letters).
'reckless' with its centre removed is 'RECESS'.
'and' acts as a link.
(Other definitions for recess that I've seen before include "Suspension of a session for a rest" , "Parliamentary downtime" , "Enclosure set back or indented" , "Temporary suspension of business" , "A niche or a temporary business break" .)