Ya

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1970s: short for young adult.

wiktionary

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Reduced form of you. Compare Dutch je, reduced/unstressed form of jij(“you”).

Apparently from German ja and cognates in other Germanic languages; related to English yeah.

From Middle English ya, from Old English ġēa, iā(“yea, yes”). More at yea.

Variation of hyah.

ya

From Russian я(ja).