quid pro quo /kwid prō kwō/

1. Something given or taken as equivalent to another, often as retaliation or in return for a previous favour
2. The action or fact of giving or receiving thus

• mark-white
• mark-whites
• mark with a white stone
• marl
• marled
• marlier
• marliest
• marlin
• marline
• marlines
• marline-spike
• marline-spikes
• marling
• marlings
• marlins
• marlinspike
• marlinspikes
• marl-pit
• marl-pits
• marls
• marlstone
• marlstones
• marly
• marm
• marmalade