Pete's stumbling and falling sharply (5)
I believe the answer is:
steep
'and falling sharply' is the definition.
I can't tell whether this definition defines the answer.
'pete's stumbling' is the wordplay.
'stumbling' is an anagram indicator.
'petes' anagrammed gives 'STEEP'.
Can you help me to learn more?
(Other definitions for steep that I've seen before include "Precipitous - outrageous" , "Quickly rising" , "Having a sharp incline" , "Stiff - thoroughly wet" , "Almost perpendicular" .)