from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Of, relating to, or having three dimensions.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. three-dimensional
from the GNU version of the Collaborative International Dictionary of English
- adj. Having three dimensions; extended in three different directions.
from The Century Dictionary and Cyclopedia
- Having three (and only three) dimensions—that is, length, breadth, and thickness; of or relating to space so characterized.
tri- + dimensional (Wiktionary)