Definition: The word "anorthosite" comes from ancient Greek and means "solid stone." In Hebrew, it's used to refer to a hard, unyielding substance that is very resistant to crushing or cracking. Definition: An orthos refers to something solid, like stone, which cannot be broken or crushed. It also describes something strong, like iron, which does not easily break or deform under pressure. An orthosite can also mean an object that cannot be changed by any means other than its own natural state, like a solid stone.