noun
- The cardinal number that is the sum of three and one.
- synonyms: four, 4, IV, quatern, quaternion, quaternary, quaternity, quartet, quadruplet, foursome, Little Joe
WordNet 3.0 © 2006 by Princeton University
| APA | WordNet. (2010). tetrad. Retrieved September 21, 2026, from http://smartdefine.org/tetrad/definitions/1315661 |
| Chicago | WordNet. 2010. "tetrad" http://smartdefine.org/tetrad/definitions/1315661 (accessed September 21, 2026). |
| Harvard | WordNet 2010, tetrad, Smart Define, viewed 21 September, 2026, <http://smartdefine.org/tetrad/definitions/1315661>. |
| MLA | WordNet. "tetrad" 23 October 2010. Web. 21 September 2026. <http://smartdefine.org/tetrad/definitions/1315661> |