Frequently remove roof from top of house (3)
I believe the answer is:
oft
'frequently' is the definition.
(synonyms)
'remove roof from top of house' is the wordplay.
'remove roof from' means to remove the first letter (in a down clue, the roof is the letter at the top).
'top of house' becomes 'loft' (space at the top of a house).
'loft' with its first letter taken away is 'OFT'.
(Other definitions for oft that I've seen before include "Consistently" , "Frequently, as the poet would have it" , "Frequently in archaic term" , "(Poetically) frequently" , "time and again in literature" .)