Meaning

adjective distant but within sight (`yon' is dialectal)

adverb at or in an indicated (usually distant) place (`yon' is archaic and dialectal); ; - Calder Willingham

originFrom Middle English yonder, yondre, ȝondre, ȝendre, from Old English ġeonre (“thither; yonder”, adverb), equivalent to yond (from ġeond, from Proto-Germanic *jainaz) + -er, as in hither, thither. Cognate with Scots ȝondir (“yonder”), Saterland Frisian tjunder (“over there, yonder”), Dutch ginder (“over there; yonder”), Middle Low German ginder, gender (“over there”), German jenseits (“on the…

Etymology from Wiktionary, CC BY-SA 3.0