Efeu m, n (genitive Efeus, no plural)
From Middle High German ephöu, from Old High German ebhouwi, derived through popular association with houwi (“hay”) from older ebah. Possibly from Proto-Germanic *ibahs, from Proto-Indo-European *(h₁)ebʰ-. The spelling and pronunciation in modern German used to be Epheu [ˈeːpˌhɔʏ̯]. The contemporary -f- is a spelling pronunciation that emanated from the North, reinforced by forms in Central and Low German dialects with original -f- (compare Middle Low German īflōf, ifflōf, Ripuarian Effche). Akin to English ivy.