Related Clues:

• Soloist?
• Loner, plus
• 57-Across, e.g.
• No mixer
• Not the gregarious type
• Unsociable sort
• Hermit, e.g.
• One not mingling much
• Hardly a company man
• One who doesn't mingle
• He doesn't get out much
• Garbo, by choice
• Leaver of the pack?
• One averse to mingling
• Antisocial person