In burrow, northern insect getting heated (9)
I believe the answer is:
indignant
'heated' is the definition.
(thesaurus)
'in burrow northern insect' is the wordplay.
'burrow' becomes 'dig' (I've seen this before).
'northern' becomes 'n' (abbreviation e.g. N. Ireland).
'insect' becomes 'ant' (ant is a kind of insect).
'in'+'dig'+'n'+'ant'='INDIGNANT'
'getting' is the link.
(Other definitions for indignant that I've seen before include "Affronted by perceived injustice" , "Annoyed at unfair treatment" , "to get angry" , "Somewhat outraged" , "Anger at having been treated unjustly" .)