E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
A morris dance, or the boy in the morris dance, called Mad Morion, from the morion which he wore on his head. (See MORRIS DANCE.) Maid Marian is a corruption first of the words, and then of the sex. Having got the words Maid Marian, etymologists have puzzled out a suitable character in Matilda, the daughter of Fitz-Walter, baron of Bayard and Dunmow, who eloped with Robert Fitz-Ooth, the outlaw, and lived with him in Sherwood Forest. Some refine upon this tale, and affirm that Matilda was married to the outlaw (commonly called Robin Hood) by Friar Tuck.
A set of morrice dancers danced a maidmarian with a tabor and pipe.Temple.