Lloegyr

The people of Lloegyr were called Lloegyrwys without distinction of ethnicity, the term applying to both Britons and Anglo-Saxons.

The word has been anglicised and Latinised into such forms as Logres, Logris, and Loegria, among others, and is perhaps most widely recognised as the name of King Arthur's realm in the body of literature known as the Matter of Britain.

12th century AD author Geoffrey of Monmouth offered a fanciful etymology in his Historia regum Britanniae, deriving the names of Cambria, Loegria, and Albany from the sons of Brutus of Troy: Camber, Locrinus, and Albanactus, respectively, and makes them the eponymous kings of Wales/Cambria (Camber), England/Loegria (Locrinus), and Scotland/Albany (Albanactus).

regard the Old Irish word as a loan from Late Latin lāicus ‘layman; of the people’), from a Proto-Indo-European root *leh2- "war".

[12] Richard Coates makes a suggestion which agrees semantically with Matasović's, but proposes instead that it is borrowed from West Germanic (i.e. pre-Old English) *laikārōs ‘performers of exploits, players (in a military sense), warriors’.