Last symbol of resistance? (5)
I believe the answer is:
omega
This clue is a double definition.
'last' is the first definition.
(I've seen this before)
'symbol of resistance?' is the second definition.
(I've seen this before)
(Other definitions for omega that I've seen before include "Greek long 'o'" , "Consummation" , "long letter" , "symbol of resistance?" , "Ending of a series or sequence" .)