All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Imaam Al-Fayyoomi wrote in his book “Al-Misbaah Al-Muneer”, "Al-Ka'bah is so named due to its height and due to its square shape." The Ka'bah also literally means a room.
Allaah Knows best.