late 14c., "parti-colored, variegated in color" (originally of fabric), from Anglo-French motteley, a word of unknown origin, perhaps [OED] based on Old English mot "speck" or a cognate Germanic word (see mote). But Klein's sources say probably from Gaulish. Century Dictionary rejects both. "Diversified in color," especially of a fool's dress. Hence, allusively, "a fool" (1600). As a noun meaning "cloth of contrasting mixed color" from late 14c.
"a pattern or arrangement of marks or blotches of different colors or shades," 1670s, probably a back-formation from motley.
evergreen tree of temperate Europe and Asia, Old English iw, eow "yew," from Proto-Germanic *iwo- (source also of Middle Dutch iwe, Dutch ijf, Old High German iwa, German Eibe, Old Norse yr), from PIE *ei-wo- (source also of Old Irish eo, Welsh ywen "yew"), perhaps a suffixed form of root *ei- (2) "reddish, motley, yellow."
OED says French if, Spanish iva, Medieval Latin ivus are from Germanic (and says Dutch ijf is from French); others posit a Gaulish ivos as the source of these. Lithuanian ieva likewise is said to be from Germanic. The tree symbolizes both death and immortality, being poisonous as well as long-lived. Reference to its wood as well-suited to making bows dates from c. 1400.