"Especially of a leaf, calyx, etc.: divided in five sections to about halfway; five-cleft", Early 18th cent.; earliest use found in Philosophical Transactions of the Royal Society of London. From post-classical Latin quinquifidus divided into five, (of a leaf) divided into five sections from classical Latin quīnque- + -fīdus.[quinquefid etymology, quinquefid origin, 英语词源]