regency
Concise Oxford English Dictionary © 2008 Oxford University Press:
regency /ˈriːdʒ(ə)nsi/
▶noun (pl. regencies) the office or period of government by a regent.
■ a commission acting as regent.
■ (the Regency) the period of a particular regency, especially (in Britain) from 1811 to 1820 and (in France) from 1715 to 1723.
▶adjective (Regency) relating to or denoting a broadly neoclassical style of British architecture, clothing, and furniture of the late 18th and early 19th centuries.'regency' also found in these Oxford entries:

