Doublet may refer to:Doublet (clothing), a man's snug-fitting buttoned jacket that was worn from the late 14th century to the mid 17th centuryDoublet (lapidary), an assembled gem composed in two sections, such as a garnet overlaying green glassDoublet (lens), a type of lens, made up of two stacked layers with different refractive indicesDoublet (linguistics), one of two or more words of the same language that come from the same rootDoublet (physics), a quantum state of a system with a spin of 1/… (More on Doublet)