köken: Borrowed from Medieval Latin ad Deum (“to God”). Compare Aragonese, Asturian, Extremaduran, and Spanish adiós, Catalan adeu, Dutch ajuus, English, French, and Occitan adieu, German tschüss, Greek αντίο (antío), Galician adeus, Italian addio, Maltese addiju, Mirandese adius, Romanian adio, Serbo-Croatian ади̏о/adȉo, Slovene adȋjo.
köken: Originally a compound of 御 (o-, honorific prefix) + 早く (hayaku, “early”, adverb), from adjective 早い (hayai, “early”). Modern Japanese -i adjectives formerly ended in -ki for the attributive form. This medial /k/ dropped out during the Muromachi period, both for the attributive form (-ki becoming -i) and for the adverbial form (-ku becoming -u). However, the adverbial form reverted back to -ku…
köken: Blend of ciao + hello, popularised by a greeting used by Inaba Meguru (因幡 めぐる) in the game Sabbat of the Witch by YUZUSOFT, released 27th February 2015 (21st July 2023 as for the Chinese version).
köken: Borrowed from Classical Persian اَلوِدَاع (alwidā'), an unadapted borrowing from Arabic الوَدَاع (al-wadāʕ), whence also विदा (vidā, “departure”). Cognate with Turkish elveda.
hi (greeting) · hey (to get someone's attention) · bye (often repeated twice: hei hei)
köken: From Proto-Finnic *hei (compare Estonian hei, Ingrian hei, Karelian hei, Ludian hei, Veps hei). Compare also Old Norse hei (whence Swedish hej) and English hey.