Regency vs Regency era

Regency and Regency era both are nouns.

Word	Noun	Adjective	Verb	Adverb
Regency	Yes	No	No	No
Regency era	Yes	No	No	No

As nouns, Regency and Regency era are synonyms defined as:

Regency and Regency era: the period from 1811-1820 when the Prince of Wales was regent during George III's periods of insanity

Regency (noun)	Regency era (noun)
the period from 1811-1820 when the Prince of Wales was regent during George III's periods of insanity	the period from 1811-1820 when the Prince of Wales was regent during George III's periods of insanity