Excellent run produces cheers (7)
I believe the answer is:
goodbye
'cheers' is the definition.
(I've seen this before)
'excellent run' is the wordplay.
'excellent' becomes 'good'.
'run' becomes 'bye' (I've seen this before).
'good'+'bye'='GOODBYE'
'produces' acts as a link.
(Other definitions for goodbye that I've seen before include "Adieu" , "so long" , "Cheers" , "Cheerio" , "Farewell remark" .)