Related Clues:

• Desirable extra
• Companions' separator?
• "Besides . . ."
• Word used when adding?
• Word used when adding
• "Wait, there's more ..."
• Word in the name of many duos
• 'What's more ...'
• "Besides that ..."
• Furthermore...
• "On top of that"
• It precedes an extra point?
• Far-away connection?
• So-so center?
• On top of everything else