yon (adj., pron.) Look up yon at Dictionary.com
Old English geon "that (over there)," from Proto-Germanic *jaino- (cognates: Old Frisian jen, Old Norse enn, Old High German ener, Middle Dutch ghens, German jener, Gothic jains "that, you"), from PIE pronomial stem *i- (cognates: Sanskrit ena-, third person pronoun, anena "that;" Latin idem "the same," id "it, that one;" Old Church Slavonic onu "he;" Lithuanian ans "he"). As an adverb from late 15c., a shortening of yonder.