thioxene

from The Century Dictionary.

• noun A general name applied in organic chemistry to the various dimethyl-thiophenes, (CH₃)₂C₄H₂S. They are all liquids and can be prepared synthetically.

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

• noun (Chem.) Any one of three possible metameric substances, which are dimethyl derivatives of thiophene, like the xylenes from benzene.

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

• noun chemistry Any of three possible metameric substances that are dimethyl derivatives of thiophene, like the xylenes from benzene.