We found 39 dictionaries that define the word quadrilateral:

General (26 matching dictionaries)

1. quadrilateral: Longman Dictionary of Contemporary English
2. quadrilateral: Merriam-Webster
3. quadrilateral: Oxford Learner's Dictionaries
4. quadrilateral: American Heritage Dictionary of the English Language
5. quadrilateral: Collins English Dictionary
6. quadrilateral: Vocabulary.com
7. Quadrilateral, quadrilateral: Wordnik
8. quadrilateral: Cambridge Advanced Learner's Dictionary
9. quadrilateral: Wiktionary
10. quadrilateral: Webster's New World College Dictionary, 4th Ed.
11. quadrilateral: The Wordsmyth English Dictionary-Thesaurus
12. quadrilateral: Infoplease Dictionary
13. quadrilateral: Dictionary.com
14. quadrilateral (n.): Online Etymology Dictionary
15. Quadrilateral (disambiguation), Quadrilateral (horse), Quadrilateral: Wikipedia, the Free Encyclopedia
16. Quadrilateral: Online Plain Text English Dictionary
17. quadrilateral: Webster's Revised Unabridged, 1913 Edition
18. quadrilateral: Rhymezone
19. Quadrilateral: AllWords.com Multi-Lingual Dictionary
20. quadrilateral: Webster's 1828 Dictionary
21. quadrilateral: FreeDictionary.org
22. quadrilateral: Mnemonic Dictionary
23. quadrilateral: TheFreeDictionary.com
24. Quadrilateral: Dictionary of Phrase and Fable (1898)

Art (1 matching dictionary)

25. quadrilateral: ArtLex Lexicon of Visual Art Terminology

Computing (1 matching dictionary)

26. quadrilateral: Encyclopedia

Medicine (4 matching dictionaries)

27. quadrilateral: Merriam-Webster Medical Dictionary
28. Dorland's Illustrated Medical Dictionary (No longer online)
29. online medical dictionary (No longer online)
30. quadrilateral: Medical dictionary

Science (7 matching dictionaries)

31. A Glossary of Mathematical Terms (No longer online)
32. Quadrilateral: Eric Weisstein's World of Mathematics
33. Botanical Terms (No longer online)
34. quadrilateral: MATH SPOKEN HERE!
35. Quadrilateral: The Orchid Lady's Illustrated Orchid Encyclopedia
36. quadrilateral: PlanetMath Encyclopedia
37. Glossary of Entomology (No longer online)

(Note: See quadrilaterals as well.)

Definitions from Wiktionary ( ) ▸ noun:  (geometry) A polygon with four sides. ▸ noun:  An area defended by four fortresses supporting each other. ▸ adjective:  Having four sides. Similar: quadrangle, tetragon, many-sided, multilateral, four-sided, quadrilater, quadrilaterality, pentagon, quadrangularity, octagon, more... Opposite: triangle Types: square, rectangle, parallelogram, rhombus, trapezoid, kite, more... Phrases: quadrilateral space, lambeth quadrilateral, cyclic quadrilateral, complete quadrilateral, lambert quadrilateral, more... Adjectives: complete, irregular, cyclic, inscribed, famous, regular, convex, circumscribed, general, spherical, skew Colors:     blue,     red,     green,     yellow,     orange, more... ▸ Word origin ▸ Words similar to quadrilateral ▸ Usage examples for quadrilateral ▸ Idioms related to quadrilateral ▸ Wikipedia articles (New!) ▸ Popular adjectives describing quadrilateral ▸ Popular nouns described by quadrilateral ▸ Words that often appear near quadrilateral ▸ Rhymes of quadrilateral ▸ Invented words related to quadrilateral