We found 22 dictionaries that define the word capital letter:

General (16 matching dictionaries)

1. capital letter: Oxford Learner's Dictionaries
2. capital letter: American Heritage Dictionary of the English Language
3. capital letter: Vocabulary.com
4. capital-letter, capital letter: Wordnik
5. capital letter: Cambridge Advanced Learner's Dictionary
6. capital letter: Wiktionary
7. capital letter: The Wordsmyth English Dictionary-Thesaurus
8. capital letter: Infoplease Dictionary
9. Capital letter, capital letter: Dictionary.com
10. Capital letter: Wikipedia, the Free Encyclopedia
11. capital letter: Rhymezone
12. capital letter: FreeDictionary.org
13. capital letter: Mnemonic Dictionary
14. capital letter: TheFreeDictionary.com

Art (1 matching dictionary)

15. capital letter: ArtLex Lexicon of Visual Art Terminology

Business (2 matching dictionaries)

16. capital letter: Legal dictionary
17. capital letter: Financial dictionary

Computing (1 matching dictionary)

18. capital letter: Encyclopedia

Medicine (1 matching dictionary)

19. capital letter: Medical dictionary

Miscellaneous (1 matching dictionary)

20. capital letter: Idioms

(Note: See capital_letters as well.)

Definitions from Wiktionary (capital letter) ▸ noun:  An upper-case letter (A, B, C, ... as opposed to a, b, c, ...), used for emphasis, for starting sentences and proper names, etc. Similar: upper case, uppercase, capital, block capital, majuscule, caps, sentence case, initial caps, all caps, capitalisation, more... Opposite: lowercase, small letter ▸ Words similar to capital letter ▸ Usage examples for capital letter ▸ Idioms related to capital letter ▸ Wikipedia articles (New!) ▸ Words that often appear near capital letter ▸ Rhymes of capital letter ▸ Invented words related to capital letter