Nervous at the hurdles? (5)
I believe the answer is:
jumpy
'nervous' is the definition.
(synonyms)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for jumpy that I've seen before include "Jittery" , "Anxious, uneasy" , "Nervous (as beans or fleas?)" , "On edge" .)