interregnum

As a noun interregnum

is interregnum (period of time between the end of a sovereign's reign and the accession of another sovereign).

As a proper noun commonwealth is

the commonwealth of nations, a loose confederation of nations based around the former british empire.

As nouns the difference between interregnum and intervals

is that interregnum is the period of time between the end of a sovereign's reign and the accession of another sovereign while intervals is plural of lang=en.

As nouns the difference between interregnum and interlude

is that interregnum is the period of time between the end of a sovereign's reign and the accession of another sovereign while interlude is an intervening episode, etc.

As a verb interlude is

to provide with an interlude.

As nouns the difference between interregnum and interim

is that interregnum is the period of time between the end of a sovereign's reign and the accession of another sovereign while interim is a transitional or temporary period between other events.

As an adjective interim is

transitional.

As nouns the difference between intermission and interregnum

is that intermission is a break between two performances or sessions, such as at a concert, play, seminar, or religious assembly while interregnum is interregnum (period of time between the end of a sovereign's reign and the accession of another sovereign).

As nouns the difference between interregnum and interrex

is that interregnum is interregnum (period of time between the end of a sovereign's reign and the accession of another sovereign) while interrex is (history) an official in ancient rome, who acted as single head of state during the interregnum between two consulates.