We found 11 dictionaries that define the word hydrogen atom:

General (7 matching dictionaries)

1. hydrogen atom: Vocabulary.com
2. hydrogen atom: Dictionary.com
3. Hydrogen atom: Wikipedia, the Free Encyclopedia
4. hydrogen atom: Rhymezone
5. hydrogen atom: FreeDictionary.org
6. hydrogen atom: Mnemonic Dictionary
7. hydrogen atom: TheFreeDictionary.com

Computing (1 matching dictionary)

8. hydrogen atom: Encyclopedia

Medicine (2 matching dictionaries)

9. hydrogen atom, Hydrogen atom: Medical dictionary

Science (1 matching dictionary)

10. Hydrogen Atom: Eric Weisstein's World of Physics

(Note: See hydrogen_atoms as well.)

Definitions from Wikipedia (Hydrogen atom) ▸ noun:  A hydrogen atom is an atom of the chemical element hydrogen. ▸ Words similar to hydrogen atom ▸ Usage examples for hydrogen atom ▸ Idioms related to hydrogen atom ▸ Wikipedia articles (New!) ▸ Words that often appear near hydrogen atom ▸ Rhymes of hydrogen atom ▸ Invented words related to hydrogen atom