Virgo perhaps needs a large cue (6)
I believe the answer is:
signal
'cue' is the definition.
(thesaurus)
'virgo perhaps needs a large' is the wordplay.
'virgo perhaps' becomes 'sign' (virgo is a kind of sign).
'needs' is a charade indicator (letters next to each other).
'large' becomes 'l'.
'sign'+'a'+'l'='SIGNAL'
(Other definitions for signal that I've seen before include "Important; communication" , "Memorable" , "Nonverbal action or gesture that encodes a message" , "beacon" , "Silent communication" .)