Folk above ground in Wells disowning old priest (3)
I believe the answer is:
eli
'priest' is the definition.
(I've seen this before)
'folk above ground in wells disowning old' is the wordplay.
'folk above ground in wells' becomes 'eloi' (race of people in HG Wells' The Time Machine).
'disowning' suggests deleting specific letters.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'eloi' with 'o' taken out is 'ELI'.
(Other definitions for eli that I've seen before include "Religious character" , "Man" , "Highest priest at Shiloh" , "- Whitney invented the cotton gin in seventeen ninety three" , "Old Testament high priest" .)