Flexible notice father put up on board (9)
I believe the answer is:
adaptable
'flexible' is the definition.
(similar in meaning)
'notice father put up on board' is the wordplay.
'notice' becomes 'ad' (short for advert).
'father' becomes 'pa' (pa can mean dad or father).
'put up' says the letters should be written backwards.
'on' is a charade indicator (letters next to each other).
'board' becomes 'table' (both can mean food).
'pa' back-to-front is 'ap'.
'ad'+'ap'+'table'='ADAPTABLE'
(Other definitions for adaptable that I've seen before include "Versatile" , "Flexible, pliant" , "Flexible, adjustable" , "Good at fitting in to new situations" , "Good at fitting in to new circumstances" .)