Scud came to ground as usual (10)
I believe the answer is:
accustomed
'usual' is the definition.
(thesaurus)
'scud came to ground' is the wordplay.
'ground' indicates anagramming the letters (grind the letters ).
'scud'+'came'+'to'='scudcameto'
'scudcameto' anagrammed gives 'ACCUSTOMED'.
'as' acts as a link.
(Other definitions for accustomed that I've seen before include "familiar" , "Used to" , "usual" .)