One Cancels the Other (OCO) Order

A pair of orders, typically limit orders, whereby if one order is filled, the other order will automatically be cancelled. For example, an OCO order might consist of an order to buy 10 calls with a strike price of 50 at a specified price or buy 20 calls with a strike price of 55 (with the same expiration date) at a specified price.

Source: Commodity Futures Trading Commission