/ ˈkɒmənwelθ; NAmE ˈkɑːm-/ noun [ sing. ]
1.
the Commonwealth an organization consisting of the United Kingdom and most of the countries that used to be part of the British Empire :
a member of the Commonwealth
Commonwealth countries
2.
(usually the Commonwealth ) used in the official names of, and to refer to, some states of the US (Kentucky, Massachusetts, Pennsylvania and Virginia) :
the Commonwealth of Virginia
The city and the Commonwealth have lost a great leader.
3.
( NAmE ) an independent country that is strongly connected to the US :
Puerto Rico remains a US commonwealth, not a state.
4.
(usually Commonwealth ) used in the names of some groups of countries or states that have chosen to be politically linked with each other :
the Commonwealth of Independent States (CIS)
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WORD ORIGIN
late Middle English (originally as two words, denoting public welfare): from common + wealth .