polytungstic

from The Century Dictionary.

• Noting an acid which may be viewed as containing two or more combining units of tungsten trioxid combined with the elements of water, as metatungstic acid, H₂W₄O₁₃ = H₂O₁ (WO₃)₄.

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

• adjective (Chem.) Containing several tungsten atoms or radicals.
• adjective (Chem.) any one of several complex acids of tungsten containing more than one atom of tungsten.

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

• adjective obsolete (chemistry) Of or pertaining to polytungstic acid