Still husband has strong exterior (6)
I believe the answer is:
though
'still' is the definition.
(thesaurus)
'husband has strong exterior' is the wordplay.
I cannot quite see how this works, but
'husband' could be 'h' and 'h' is found within the answer.
'strong' could be 'tough' (synonyms) and 'tough' is present in the leftover letters.
This accounts for all the letters.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for though that I've seen before include "Concessive conjuction" , "Even if" , "Nevertheless" , "Despite the fact that" , "However" .)