Mac and Mainframe

Mac noun - A coat made of water-resistant material.

Mainframe and mac are semantically related in calculating topic. In some cases you can use "Mainframe" instead a noun "Mac", when it comes to topics like computer.

Mainframe noun - A large digital computer serving 100-400 users and occupying a special air-conditioned room.

Mac and mainframe are semantically related in calculating topic. You can use "Mac" instead a noun "Mainframe", if it concerns topics such as computer.