Used something on the face? (6,4)
I believe the answer is:
second hand
This clue is a double definition.
'used' is the first definition.
(I've seen this before)
'something on the face?' is the second definition.
(the second hand on a clockface)
(Other definitions for second hand that I've seen before include "Watch component" , "going quickly on the clock?" , "not original" , "Part of a timepiece" , "Previously owned - part of watch" .)