Inclined to have answer in forty days (5)
I believe the answer is:
leant
'inclined' is the definition.
(I've seen this before)
'answer in forty days' is the wordplay.
'answer' becomes 'a' (abbreviation eg in Q and A).
'in' means one lot of letters goes inside another.
'forty days' becomes 'lent' (I've seen this before).
'a' going within 'lent' is 'LEANT'.
'to have' is the link.
(Other definitions for leant that I've seen before include "bent over" , "pressed on" , "Rested sideways (on something)" , "Relied (on); inclined" , "Inclined (towards)" .)