noun: (obsolete) The birth of two or more things at the same time; A simultaneous coming into being.
noun: The state of being born into the same family, race, or group; a commonality of heritage or birthright.
noun: (obsolete) The act of growing or developing together.
noun: (software engineering) A relationship between two or more elements of software in which changing one necessitates changing the others in order to maintain overall correctness; a metric for such a relationship.
