Trustworthy creeps about to join the board (11)
I believe the answer is:
respectable
'trustworthy' is the definition.
Both the definition and answer are adjectives. Perhaps you can see an association between them that I can't see?
'creeps about to join the board' is the wordplay.
'about' indicates anagramming the letters.
'to join' means one lot of letters go next to another.
'the board' becomes 'table' (both can mean food).
'creeps' is an anagram of 'respec'.
'respec'+'table'='RESPECTABLE'
Can you help me to learn more?
(Other definitions for respectable that I've seen before include "OK" , "fit for proper society?" , "Fairly well-to-do" , "Decent" , "Proper and good" .)