Vernacular expression for a foolish graduate intern (9)
I believe the answer is:
idiomatic
'vernacular' is the definition.
(I've seen this before)
'expression for a foolish graduate intern' is the wordplay.
'expression' becomes 'idiom' (idiom is a kind of expression).
'for' says to put letters next to each other.
'foolish graduate intern' becomes 'tic' (I can't explain this - if you can you should give a lot more credence to this answer).
'idiom'+'a'+'tic'='IDIOMATIC'
Can you help me to learn more?
(Other definitions for idiomatic that I've seen before include "Using a particular mode of expression" , "Colloquial" , "Using characteristic speech" , "spoken like a native" , "Using common language" .)