Brown with terrible bilge evident (8)
I believe the answer is:
tangible
'evident' is the definition.
(thesaurus)
'brown with terrible bilge' is the wordplay.
'brown' becomes 'tan' (tan is a kind of brown).
'with' is a charade indicator (letters next to each other).
'terrible' indicates anagramming the letters.
'bilge' anagrammed gives 'gible'.
'tan'+'gible'='TANGIBLE'
(Other definitions for tangible that I've seen before include "Real, solid" , "Solid, can be touched" , "Bleating in clear and definite manner" , "Able to be felt" , "asset" .)