Tale one cadet spun (8)
I believe the answer is:
anecdote
'tale' is the definition.
(thesaurus)
'one cadet spun' is the wordplay.
'spun' indicates anagramming the letters.
'one'+'cadet'='onecadet'
'onecadet' is an anagram of 'ANECDOTE'.
(Other definitions for anecdote that I've seen before include "Brief story" , "Short narration" , "One acted over interesting story" , "A short tale, usually true" , "Account regarded as unreliable" .)