from skamt, neut. of skammr "short"). The only exact cognate for meaning outside Eng. was in M.Du. (cf. M.Du. mergelijc "joyful"). For vowel evolution, see bury
"Bot vchon enle we wolde were fyf, þe mo þe myryer." [c.1300]
The word had much wider senses in M.E., e.g. "pleasant-sounding" (of animal voices), "fine" (of weather), "handsome" (of dress), "pleasant-tasting" (of herbs). Merry-man "companion or follower of a knight, outlaw, etc." is attested from late 14c. The first record of merry-go-round is from 1729. Merry-bout "an incident of sexual intercourse" was low slang from 1780. Merry-begot "illegitimate" (adj.), "bastard" (n.) is from 1785. Merrie England (now frequently satirical or ironic) is 14c. meri ingland, originally in a broader sense of "bountiful, prosperous." Merry Monday was 16c. term for "the Monday before Shrove Tuesday" (Mardi Gras).