Cushion scratching head frequently (5)
I believe the answer is:
often
'frequently' is the definition.
(synonyms)
'cushion scratching head' is the wordplay.
'cushion' becomes 'soften' (synonyms).
'scratching head' means to remove the first letter (the word's head is removed).
'soften' with its initial letter removed is 'OFTEN'.
(Other definitions for often that I've seen before include "In many instances" , "Repeatedly, many times" , "occurring with frequency" , "Frequently, at short intervals" , "Frequently, many times" .)