phorone

from The Century Dictionary.

• noun An unsaturated ketone, C₉H₁₄O or diisopropylidene-acetone, made by the action of quicklime on acetone, and also in other ways. It forms large yellowish-green crystals that melt at 28° C. Its odor somewhat resembles that of the geranium.

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

• noun (Chem.) A yellow crystalline substance, having a geraniumlike odor, regarded as a complex derivative of acetone, and obtained from certain camphor compounds.

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

• noun organic chemistry The unsaturated aliphatic ketone 2,6-dimethyl-2,5-heptadien-4-one obtained from camphor; diisopropylidene acetone