Splendid fish found by Scot with time (9)
I believe the answer is:
brilliant
'splendid' is the definition.
(thesaurus)
'fish found by scot with time' is the wordplay.
'fish' becomes 'brill' (I've seen this before**).
'found by' says to put letters next to each other.
'scot' becomes 'ian'.
'with' says to put letters next to each other.
'time' becomes 't'.
'brill'+'ian'+'t'='BRILLIANT'
(Other definitions for brilliant that I've seen before include "Very bright or vivid" , "Of surpassing excellence" , "Fantastic!" , "Of outstanding ability" , "Superb" .)