Blue act entertaining crowd (9)
I believe the answer is:
depressed
'blue' is the definition.
(thesaurus)
'act entertaining crowd' is the wordplay.
'act' becomes 'deed' (deed is a kind of act).
'entertaining' indicates putting letters inside.
'crowd' becomes 'press' (press is a kind of crowd**).
'deed' going around 'press' is 'DEPRESSED'.
(Other definitions for depressed that I've seen before include "Flattened downward" , "Unhappy, despondent" , "dispirited" , "25 [BLUE]" , "Poverty-stricken" .)