Related Clues:

• Answer initially in such a pleasing way
• Letters on reply cards
• 'Please reply' abbr
• Please reply to invitation
• Letters to answer one's inviting letter?
• Invitation exhortation
• Like many restaurants without a liquor lic
• SASE enclosure, maybe
• Like Fridays, in some offices
• Word before Friday or sex
• Abbr. in many a party invitation
• Workers without fixed employment
• Relaxed - unintentional
• Can you come to the party?
• Offhand — informal