Tetramethylene

Tet′ra‐meth″yl‐ene (?), n. [Tetra- + methylene.] (Chem.) (a) A hypothetical hydrocarbon, C4H8, analogous to trimethylene, and regarded as the base of well-known series or derivatives. (b) Sometimes, an isomeric radical used to designate certain compounds which are really related to butylene.