butene

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of three gaseous isomeric ethylene hydrocarbons, C₄H₈, used principally in making synthetic rubbers.

from The Century Dictionary.

• noun The official name of the hydrocarbon C₄H₈. It exists in three isomeric forms. Also called butylene.

from the GNU version of the Collaborative International Dictionary of English.

• noun any of three isomeric singly unsaturated hydrocarbons C4H8; all are used in making synthetic rubbers; -- called also butylene.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun chemistry Any of several forms of butylene.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun any of three isomeric hydrocarbons C4H8; all used in making synthetic rubbers