aye

Etymology 1

From Middle English ay, ai, aȝȝ, from Old Norse ei, ey, from Proto-Germanic *aiwa, *aiwō (“ever, always”) (compare Old English āwo, āwa, ā, ō, Middle Dutch ie, German je), from *aiwaz (“age; law”) (compare Old English ǣ(w) (“law”), West Frisian ieu (“century”), Dutch eeuw (“century”)), from Proto-Indo-European *h₂eyu- (“long time”) (compare Irish aois (“age, period”), Breton oad (“age, period”), Latin ævum (“eternity”), Ancient Greek αἰών (aiṓn)). Doublet of aeviternity and aevum.

adv

1. (archaic) ever, always
   The ship drove fast, loud roared the blast, / And southward aye we fled. 1834, Samuel Taylor Coleridge, The Rime of the Ancient Mariner
   Let the Amen sound from His people again; Gladly for aye we adore Him. (Praise to the Lord, the Almighty) 1863, Translation by Catherine Winkworth

Etymology 2

"Appears suddenly about 1575, and is exceedingly common about 1600." Probably from use of aye (“ever, always”) as expression of agreement or affirmation, or from Middle English a ye (“oh yes”), or synthesis of both. More at oh, yea.

intj

1. yes; yea; a word expressing assent, or an affirmative answer to a question.
2. (nautical) a word used to acknowledge a command from a superior, usually preceded by a verbatim repeat-back.

noun

1. An affirmative vote; one who votes in the affirmative.
   "To call for the ayes and nays;" "The ayes have it."

Etymology 3

Probably of multiple motivations, the sounds having been chosen for functional reasons.

intj

1. (MLE, MTE, regional African-American Vernacular) an attention grabber
   Aye, come here!
   Aye, what do you have?
2. (New Zealand) Alternative spelling of ay (question tag)