Bittersweet

wiktionary

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From Middle English bitterswete, biterswete, equivalent to bitter +‎ sweet. Cognate with Saterland Frisian bitterswäit(“bittersweet”), West Frisian bittersoet(“bittersweet”), Dutch bitterzoet(“bittersweet”), German bittersüß(“bittersweet”), Danish bittersød(“bittersweet”), Swedish bittersöt(“bittersweet”).

etymonline

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bittersweet (adj.)

"uniting bitterness and sweetness," 1610s, from bitter (adj.) + sweet (adj.). Perhaps older, as the same word is used as a noun in Middle English (late 14c.) for drinks or experiences that are both bitter and sweet and especially in reference to a type of apple; later of woody nightshade (1560s). Greek had a similarly formed compound, glykypikros, literally "sweet-bitter."