Affixes

A dodecahedron (Greek hedra, seat, base) is a three-dimensional shape having twelve plane faces, while a dodecagon is a plane figure with twelve straight sides and angles. The Dodecanese is a group of twelve islands in the SE Aegean. The term dodecaphonic refers to a system of musical composition, also called the twelve-note or twelve-tone system.

In chemistry, dodecane is the straight chain (aliphatic) hydrocarbon C₁₂H₂₆; dodecyl (see ‑yl) relates to the radical C₁₂H₂₅—, as in dodecyl aldehyde, also called lauric aldehyde or dodecanal (see ‑al²), used in perfumery; dodecanoic acid (see ‑oic), or lauric acid, occurs in many vegetable fats and is used to make soaps and cosmetics.