It makes sense to Henry, nevertheless (6)
I believe the answer is:
withal
'nevertheless' is the definition.
(synonyms)
'it makes sense to henry' is the wordplay.
'it makes sense' becomes 'wit' (I can't justify this - if you can you should believe this answer much more).
'to henry' becomes 'hal' (short for Henry).
'wit'+'hal'='WITHAL'
Can you help me to learn more?
(Other definitions for withal that I've seen before include "To boot" , "it's all the same to Shakespeare" , "as well" , "Despite that, notwithstanding" , "nevertheless" .)