Butylene \Bu"ty*lene\, n. [From {Butyl}.]
1. (Chem.) Any one of three metameric hydrocarbons, {C4H8},
of the ethylene series. They are gaseous or easily
liquefiable; -- called also {butene}.
[1913 Webster]
2. the hypothetical divalent radical {-(CH2)4-}; -- used in
combining forms; as, butylene diamine.
[PJC]