Doctor given pound beheaded old priest (5)
I believe the answer is:
druid
'old priest' is the definition.
(I've seen this before)
'doctor given pound beheaded' is the wordplay.
'doctor' becomes 'Dr' (abbreviation).
'given' says to put letters next to each other.
'pound' becomes 'quid' (UK slang for a pound).
'beheaded' means to remove the first letter (the head of the word is removed).
'quid' with its first letter taken off is 'uid'.
'dr'+'uid'='DRUID'
(Other definitions for druid that I've seen before include "Old Celtic priest" , "Pre-Christian Celtic priest" , "Ancient priest of Wales" , "Celtic soothsayer" , "Ancient Celt priest" .)