Premium Bond selector (5)
I believe the answer is:
ernie
'premium bond selector' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for ernie that I've seen before include "One regularly drawing" , "Sergeant Bilko, for one" , "It picks Premium Bond winners" , "--- Wise, comedian" , "___ Wise, d. 1999" .)