Crank (up) (3)
I believe the answer is:
rev
'crank up' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for rev that I've seen before include "Increase speed of (an engine)" , "Accelerate (abbrev.)" , "Clergyman, or woman (abbr)" , "serviceman?" , "Clergy title" .)