Very loud seaman in the drink? Gracious! (7)
I believe the answer is:
affable
'gracious' is the definition.
(thesaurus)
'very loud seaman in the drink?' is the wordplay.
'very loud' becomes 'ff' (musical abbreviation).
'seaman' becomes 'ab'.
'in the' is an insertion indicator.
'drink?' becomes 'ale' (ale is a kind of drink).
'ff'+'ab'='ffab'
'ffab' going inside 'ale' is 'AFFABLE'.
(Other definitions for affable that I've seen before include "nice" , "Showing friendly warmth" , "Warm and friendly" , "Pleasantly friendly" , "Pleasant and easygoing" .)