Dipstick's measurement (5)
I believe the answer is:
depth
'dipstick's measurement' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for depth that I've seen before include "Distance from top down as in water" , "sometimes leading to charge for sailors at war?" , "Distance from the surface to the bottom" , "Measurement from front to back" , "Downward extent" .)