the GNU version of the Collaborative International Dictionary of English
adj. Pertaining to a decagon; having ten sides.
The Century Dictionary and Cyclopedia
Pertaining to or being a decagon; having ten sides.
Word Usage
"“Straight edges and compasses work fine for the recurring symmetries of the simplest patterns we see, but it probably required far more powerful tools to fully explain the elaborate tiling with decagonal 10-sided symmetry,” Mr Lu said."