Lot Sale
Selling multiple items together as a single listing. Common on eBay for bulk lots (e.g. '10 x women's size 10 dresses'). Lower per-item price but faster clearance for hard-to-sell stock.
Where you'll see this
This term is commonly used on:
ebayfacebook-marketplace
Put this into practice
Shopfront handles the hard parts of crosslisting and inventory sync so you can focus on finding and selling.