E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Merrie England
may probably mean illustrious, from the old Teutonic mer. (Anglo-Saxon, mara, famous.) According to R. Ferguson, the word appears in the names Marry, Merry, Merick; the French Méra, Merick; Merey, Mériq; and numerous others
(Teutonic Name-System, p. 368.) (See below MERRY.)