Extremely vague, silly, idle - like some threats (6)
I believe the answer is:
veiled
'like some threats' is the definition.
(I've seen this in another clue)
'extremely vague silly idle' is the wordplay.
'extremely' means to remove the middle letters (only the extremes of the word are used).
'silly' indicates anagramming the letters.
'vague' with its middle removed is 've'.
'idle' anagrammed gives 'iled'.
've'+'iled'='VEILED'
(Other definitions for veiled that I've seen before include "Thinly covered, face or threat" , "Partially concealed as with gauzy stuff" , "Covered or obscure, perhaps a reference (6)" , "Covered, hidden" , "Levied, being covered up" .)