Possible Clues:

• Idealised representation of current Chairman taking in government
• Setter's past the mature stage
• It's possible I shall leave, taking a year off, before the end of the grub
• I am past the adult stage
• Gordius is past a perfect state
• 'American ___' (journal co-founded in 1939 by Freud)
• Fully-developed insect
• Grown-up gadfly
• Form of insect - imagines more than one
• How perhaps one claims to be a green light for the perfect insect