We found 27 dictionaries that define the word periodic table:

General (18 matching dictionaries)

1. periodic table: Longman Dictionary of Contemporary English
2. periodic table: Merriam-Webster
3. periodic table: Oxford Learner's Dictionaries
4. periodic table: American Heritage Dictionary of the English Language
5. periodic table: Collins English Dictionary
6. periodic table: Vocabulary.com
7. the periodic table: Cambridge Advanced Learner's Dictionary
8. periodic table: Wiktionary
9. periodic table: The Wordsmyth English Dictionary-Thesaurus
10. periodic table: Infoplease Dictionary
11. Periodic Table: Dictionary.com
12. Periodic Table, Periodic table (crystal structure), Periodic table (detailed), Periodic table (detailed cells), Periodic table (disambiguation), Periodic table (electron configurations), Periodic table (extended), Periodic table (large cells), Periodic table (large version), Periodic table (metals and non-metals), Periodic table (metals and nonmetals), Periodic table (standard), Periodic table (valence), Periodic table, The Periodic Table (Simon Basher book), The Periodic Table (book), The Periodic table: Wikipedia, the Free Encyclopedia
13. periodic table: Rhymezone
14. periodic table: FreeDictionary.org
15. periodic table: Mnemonic Dictionary
16. periodic table: TheFreeDictionary.com

Computing (1 matching dictionary)

17. The Periodic Table, periodic table: Encyclopedia

Medicine (2 matching dictionaries)

18. periodic table: Merriam-Webster Medical Dictionary
19. The Periodic Table, periodic table: Medical dictionary

Science (4 matching dictionaries)

20. From Stargazers to Starships Glossary (No longer online)
21. Periodic Table: Eric Weisstein's World of Chemistry
22. Periodic table: NRC Glossary of Nuclear Terms --
23. periodic table: UNCChem Glossary

Slang (1 matching dictionary)

24. Periodic Table: Urban Dictionary

Tech (1 matching dictionary)

25. Explosives (No longer online)

(Note: See periodic_tables as well.)

Definitions from Wiktionary (periodic table) ▸ noun:  (chemistry) A tabular chart of the chemical elements according to their atomic numbers so that elements with similar properties are in the same group (column). Similar: group, chemical series, main group, transition element, carbon group, chemical structure, main group element, chemical element, chemical symbol, representative element, more... Opposite: chaos, disorder, randomness Phrases: periodic table of the elements, the periodic table, mendeleev periodic table, organization of the periodic table, periodic table elements, more... Adjectives: molecular, gas, period, chemical, nascent, metal, compound, splitting, chymical, purum, suprafacial ▸ Words similar to periodic table ▸ Usage examples for periodic table ▸ Idioms related to periodic table ▸ Wikipedia articles (New!) ▸ Words that often appear near periodic table ▸ Rhymes of periodic table ▸ Invented words related to periodic table