mesityl

from The Century Dictionary.

• noun An organic radical, C₆H₁₀, whose oxid yields acetone by hydration.

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

• noun (Chem.) A hypothetical radical formerly supposed to exist in mesityl oxide.
• noun (Chem.) a volatile liquid having the odor of peppermint, obtained by certain dehydrating agents from acetone; -- formerly called also dumasin.

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

• noun organic chemistry, especially in combination The divalent radical (CH3)2=CH-C(CH3)=