commonwealth (n.)

mid-15c., commoun welthe, "a community, whole body of people in a state," from common (adj.) + wealth (n.). Specifically "state with a republican or democratic form of government" from 1610s. From 1550s as "any body of persons united by some common interest." Applied specifically to the government of England in the period 1649-1660, and later to self-governing former colonies under the British crown (1917). In the U.S., it forms a part of the official name of Pennsylvania, Massachusetts, Virginia, Kentucky, and Puerto Rico but has no special significance.