Lean slightly (4)
I believe the answer is:
tilt
'lean slightly' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tilt that I've seen before include "Inclination, joust" , "Engage in a medieval joust - lean" , "Thrust with lance, like Don Quixote at windmills" , "Heel over" , "Slight inclination" .)