What does Boxing Day have to do with boxing?
Old English ifig, from West Germanic *ibakhs (cf. Middle Low German iflof, Dutch eiloof, Old High German ebahewi, German Efeu), of unknown origin; the second element in the Old High German word might be "hay."
Ivy bush as a sign of a tavern where wine is served is attested from mid-15c. Ivy League, inspired by the notion of old, ivy-coated walls, dates to 1933 (perhaps originally in reference to football; it consists of Brown, Columbia, Cornell, Dartmouth, Harvard, Pennsylvania, Princeton, and Yale).