Silver bird, competent and pleasant (9)
I believe the answer is:
agreeable
'pleasant' is the definition.
(similar in meaning)
'silver bird competent' is the wordplay.
'silver' becomes 'Ag' (Ag is the chemical symbol for silver).
'bird' becomes 'ree' (I've seen this in other clues).
'competent' becomes 'able' (similar in meaning).
'ag'+'ree'+'able'='AGREEABLE'
'and' acts as a link.
(Other definitions for agreeable that I've seen before include "sympathetic" , "Willing - nice" , "In harmony; pleasant" , "Cordial" , "delightful" .)