Greek fire and Weapon system

Greek fire noun - A mixture used by Byzantine Greeks that was often shot at adversaries; catches fire when wetted.

Weapon system and Greek fire are semantically related. In some cases you can use "Weapon system" instead a noun phrase "Greek fire".

Weapon system noun - Any instrument or instrumentality used in fighting or hunting.

Greek fire and weapon system are semantically related. Sometimes you can replace phrase "Greek fire" with "Weapon system", this phrases are similar.