The story
From a putative combinative form of lemon + -in. (See also Old French lymon (“citrus”), Italian limone (“lemon”), both from Arabic لَيْمُون (laymūn).) Compare limonoid, limonene.
Etymology from Wiktionary, CC BY-SA 4.0.
limonin
Today it means: A limonoid found in orange and lemon seeds. Full definition →