Races round in panic (5)
I believe the answer is:
scare
'panic' is the definition.
(I know that panic can be written as scare)
'races round' is the wordplay.
'round' is an anagram indicator.
'races' with letters rearranged gives 'SCARE'.
'in' is the link.
(Other definitions for scare that I've seen before include "Frighten or intimidate" , "Panic" , "Cause fright, alarm" , "Greatly frighten" , "Health worry" .)