Nonsense at end of debate is spin (6)
I believe the answer is:
rotate
'is spin' is the definition.
(thesaurus)
'nonsense at end of debate' is the wordplay.
'nonsense' becomes 'rot' (I've seen this before).
'end of' suggests the final letters.
The final letter of 'debate' is 'e'.
'rot'+'at'+'e'='ROTATE'
(Other definitions for rotate that I've seen before include "Turn around on axis or central point" , "Make to spin around" , "roll" , "Turn around as on axle or spit" , "Revolve" .)