from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Three-edged; having three salient angles: triquetrous mandibles.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Having three corners or sides; triangular.
from the GNU version of the Collaborative International Dictionary of English
- adj. Three sided, the sides being plane or concave; having three salient angles or edges; trigonal.
from The Century Dictionary and Cyclopedia
- Three-sided; triangular; having three plane or concave sides
From Latin triquetrus, three-cornered : tri-, tri- + -quetrus, -cornered.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Latin triquetrus. (Wiktionary)