Kalmar “quartic” sifa ce da ke nuni da wani abu da ke da alaka da mataki na hudu ko tsari, musamman a fannin lissafi. A cikin algebra, ma'auni na quartic shine nau'in nau'in nau'i na digiri na hudu, wanda za'a iya rubuta shi a cikin sigar ax^4 bx^3 cx^2 dx e = 0, inda a, b, c, d, da e sune akai-akai da x shine m. Hakanan za'a iya amfani da kalmar "quartic" don kwatanta siffar geometric ko lanƙwasa wanda ke da ma'auni na aikin quartic.