Governor drawing the line with this? (5)
I believe the answer is:
ruler
This clue is a double definition.
'governor' is the first definition.
(I've seen this before)
'drawing the line with this?' is the second definition.
(a ruler can be used to draw lines)
(Other definitions for ruler that I've seen before include "Measuring strip" , "person holding sway?" , "Straight edge; governor" , "Person in charge of country" , "overlord" .)