Loud cur is surprisingly laughable (9)
I believe the answer is:
ludicrous
'laughable' is the definition.
(I know that laughable can be written as ludicrous)
'loud cur is surprisingly' is the wordplay.
'surprisingly' is an anagram indicator (a surprising ordering of the letters).
'loud'+'cur'+'is'='loudcuris'
'loudcuris' anagrammed gives 'LUDICROUS'.
(Other definitions for ludicrous that I've seen before include "Absurd, ridiculous" , "Utterly laughable" , "Ridiculously foolish" , "Risible" , "Farcical" .)