Microstate

Sovereign state having a very small population or very small land area

A microstate or ministate is a sovereign state having a very small population or land area, usually both. However, the meanings of "state" and "very small" are not well-defined in international law. Some recent attempts to define microstates have focused on identifying qualitative features that are linked to their size and population, such as partial delegation of their sovereignty to larger states, such as for international defense.

This keyword could refer to multiple things. Here are some suggestions: