Affectionate; heat (4)
I believe the answer is:
warm
This clue is a double definition.
'affectionate' is the first definition.
(synonyms)
'heat' is the second definition.
(to warm something up is to heat it)
(Other definitions for warm that I've seen before include "Cordial" , "Animated" , "Moderately hot" , "Lively" , "Near to finding hidden object" .)