Resent having to be incredibly rugged (8)
I believe the answer is:
begrudge
'resent' is the definition.
(synonyms)
'to be incredibly rugged' is the wordplay.
'incredibly' indicates anagramming the letters.
'rugged' is an anagram of 'grudge'.
'be'+'grudge'='BEGRUDGE'
'having' acts as a link.
(Other definitions for begrudge that I've seen before include "Envy, resent having to give" , "Envy, have feeling of resentment" , "Envy the pleasure of" , "Be resentful of" , "Envy, resent other's good fortune" .)