Bales out in a panic, that's definite (8)
I believe the answer is:
absolute
'definite' is the definition.
(thesaurus)
'bales out in a panic' is the wordplay.
'in a panic' is an anagram indicator.
'bales'+'out'='balesout'
'balesout' anagrammed gives 'ABSOLUTE'.
'that's' is the link.
(Other definitions for absolute that I've seen before include "Literary captain" , "Total; not relative" , "Complete and unrestricted, say power" , "Total; unqualified" , "Complete, full" .)