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.