n. 丁烯

[ noun ]
any of three isomeric hydrocarbons C4H8; all used in making synthetic rubbers
<noun.substance>

butene \butene\ n.
any of three isomeric singly unsaturated hydrocarbons {C4H8};
all are used in making synthetic rubbers; -- called also
{butylene}.
[WordNet 1.5]


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}.

2. the hypothetical divalent radical {-(CH2)4-}; -- used in
combining forms; as, butylene diamine.
[PJC]