Moderate losing head time after time (5)
I believe the answer is:
often
'time after time' is the definition.
(I've seen this in another clue)
'moderate losing head' is the wordplay.
'moderate' becomes 'soften' (synonyms).
'losing head' means to remove the first letter.
'soften' with its initial letter taken off is 'OFTEN'.
(Other definitions for often that I've seen before include "Frequently, habitually" , "Frequently, not seldom" , "A lot" , "Regularly" , "occurring with frequency" .)