Complex sentence: An unmanned combat aerial vehicle (UCAV), also known as a combat drone or simply a drone, is an unmanned aerial vehicle (UAV) that usually carries aircraft ordnance such as missiles and is used for drone strikes.
Split into simpler sentences: An unmanned combat aerial vehicle (UCAV) is a weapon of war, also known as a combat drone or simply a drone. It is an unmanned aerial vehicle (UAV) designed to carry aircraft ordnance such as missiles used for drone strikes.