Interpret without regret and worker will be loyal (8)
I believe the answer is:
constant
'loyal' is the definition.
(thesaurus)
'interpret without regret and worker will be' is the wordplay.
I cannot really understand how this works, but
'and' could be 'n' (common abbreviation for 'and') and 'n' is found within the answer.
'worker' could be 'ant' (worker is a type of ant) and 'ant' is present in the answer.
'be' could be 'cost' (synonyms) and 'cost' is found in the leftover letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for constant that I've seen before include "Faithful - unchanging" , "Always - faithful" , "Continuous" , "staying the same" , "Continuing unvarying" .)