Sensibly is supporting wife really regularly (6)
I believe the answer is:
wisely
'sensibly' is the definition.
(I've seen this before)
'is supporting wife really regularly' is the wordplay.
'supporting' means one lot of letters go next to another (in a down clue, some letters go below others).
'wife' becomes 'w' (abbreviation).
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
The alternate letters of 'really' are 'ely'.
'is' after 'w' is 'wis'.
'wis'+'ely'='WISELY'
(Other definitions for wisely that I've seen before include "how Solomon acted" , "Judiciously" , "With intelligence" , "Sensibly" , "Carefully considered, sagely" .)