Wipe out many years, say, when time drifts away (9)
I believe the answer is:
eradicate
'wipe out' is the definition.
(I know that wipe out can be written as eradicate)
'many years say when time drifts away' is the wordplay.
I cannot really see how this works, but
'many' could be 'd' and 'd' is found within the answer.
'years' could be 'era' (I've seen this before) and 'era' is found within the answer.
'when' could be 'e' (I've seen this in other clues) and 'e' is found within the answer.
'time' could be 't' (abbreviation) and 't' is found in the answer.
'away' could be 'a' (abbreviation as used in sports fixtures) and 'a' is found within the answer.
This explanation may well be incorrect...
(Other definitions for eradicate that I've seen before include "Exterminate, extinguish" , "Stamp out, remove all traces of" , "Excise" , "Dispose of" , "Completely remove" .)