Stopped unknown American that's gutted — beat badly boxing (7)
I believe the answer is:
abeyant
'stopped' is the definition.
'unknown american that's gutted beat badly boxing' is the wordplay.
'unknown' becomes 'y' (algebra).
'that's gutted' means to remove the middle letters (to gut something is to remove its insides).
'badly' indicates an anagram.
'boxing' indicates putting letters inside ('box' can mean contain, as in to put in a box).
'american' with its centre taken out is 'an'.
'beat' with letters rearranged gives 'abet'.
'y'+'an'='yan'
'yan' inserted inside 'abet' is 'ABEYANT'.
(Other definitions for abeyant that I've seen before include "Adjourned" , "temporarily suspended" , "In temporary suspension" , "in suspense" .)