Maybe retired head gathers I make amends (7)
I believe the answer is:
expiate
'make amends' is the definition.
(I've seen this in another clue)
'maybe retired head gathers i' is the wordplay.
'maybe retired' becomes 'ex' (prefix meaning former or onetime. I am not sure about the 'maybe' bit.).
'head' becomes 'pate' (humorous term for the head).
'gathers' means one lot of letters goes inside another.
'pate' enclosing 'i' is 'piate'.
'ex'+'piate'='EXPIATE'
Can you help me to learn more?
(Other definitions for expiate that I've seen before include "Make up for mistake" , "Atone for (a sin)" , "Make amends for wrongdoing" , "Do penance, make amends" , "Pay for" .)