tartrelic

from The Century Dictionary.

• Noting an acid, a deliquescent crystalline compound, C₄H₄O₅, prepared by heating tartaric acid rapidly to 180° C. It is a monobasic acidic anhydrid of tartaric acid.

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

• adjective (Chem.) Of, pertaining to, or designating, an anhydride, C4H4O5, of tartaric acid, obtained as a white crystalline deliquescent substance.