Constituent state

A constituent state is a territorial and constitutional entity forming part of a sovereign state. A constituent state holds administrative jurisdiction over a defined geographic territory and is a form of regional government.

Constituent states united in a federal union under a federal government are more specifically known as federated states.

Administrative units that are not federated but enjoy a greater degree of autonomy or self-government than others within the same country can be considered constituent states of a larger sovereign state. This relationship is called a federacy.Autonomous republics like Karakalpakstan in Uzbekistan

States existing in free association with another can be considered constituent states of a constitutional entity. For example, the Cook Islands, New Zealand and Niue constitute the three constituent countries of the Realm of New Zealand, united under a single head of state: the King or Queen of New Zealand.

The term can also be applied as an alternative to formal recognition of a secessionist state that has unilaterally declared independence, and whose de jure sovereignty remains in dispute.

...
Wikipedia