Meaning

noun (Arthurian legend) the magician who acted as King Arthur's advisor

noun small falcon of Europe and America having dark plumage with black-barred tail; used in falconry

originFrom Middle English merlioun, merlion, marlyon, merlyon, merlinge, from Old French emerillon, esmerillon, from Old Frankish *smiril (“falcon, hawk”), from Proto-Germanic *smirilaz (“falcon, merlin”). Cognate with Old High German smirl (“falcon”), Old Norse smyrill (“falcon”).

Etymology from Wiktionary, CC BY-SA 3.0