glutaconic

from The Century Dictionary.

• Noting a colorless compound, HOCO. CH₂.CH:CH.COOH, which crystallizes in prisms and melts at 152° C. It is isomeric with itaconic,: citraconic, and mesaconic acids. Also called pentenediacid or A -G-propylenedi-carboxylic acid.

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

• adjective (Chem.) Pertaining to, or derived from, an acid intermediate between glutaric and aconitic acids.