mer·lin (mûr'lĭn) n. A small falcon (Falco columbarius) of northern regions, having predominantly dark plumage and a black-striped tail. Also called pigeon hawk.
[Middle English, from Anglo-Norman merilun, from Old French esmerillon, diminutive of esmeril, of Germanic origin.]
Mer·lin (mûr'lĭn) n. In Arthurian legend, a magician and prophet who served as counselor to King Arthur.
"small, strong European falcon," c.1325, from Anglo-Fr. merilun, an aphetic form of O.Fr. esmerillon (Fr. émerillon), from Frank. *smiril (cf. O.H.G. smerlo, Ger. Schmerl "merlin"). Sp. esmerejon, It. smeriglio also are Gmc. loan-words.
Merlin
sorcerer and soothsayer in Arthurian legends, from O.Fr. form of Welsh Myrddhin, probably from O.Celt. *Mori-dunon, lit. "of the sea-hill," from *mori "sea" + dunom "hill."