We found 30 dictionaries that define the word prehistoric:

General (25 matching dictionaries)

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

Art (1 matching dictionary)

24. prehistoric: ArtLex Lexicon of Visual Art Terminology

Computing (1 matching dictionary)

25. prehistoric: Encyclopedia

Science (2 matching dictionaries)

26. Archaeology Wordsmith (No longer online)
27. Anthropology dictionary (No longer online)

Slang (1 matching dictionary)

28. prehistoric: Urban Dictionary

(Note: See prehistorically as well.)

Definitions from Wiktionary ( ) ▸ adjective:  (properly) Of or relating to the epoch before written record. ▸ adjective:  (inexact or humorous) Ancient; very old, outdated, etc. Similar: prehistorical, past, unfashionable, unstylish, out of fashion, protohistoric, protohistorical, prehorse, archaeolithic, ancient, more... Opposite: modern, contemporary, current, recent, futuristic Types: dinosaur, caveman, troglodyte, neanderthal, more... Phrases: prehistoric times, prehistoric man, prehistoric sites, prehistoric archaeology, Prehistoric art, more... Adjectives: late, early, flint, abundant, moist, elephantine, soft, interesting, unknown, history, strictest Colors:     olive,     moss green,     rust,     ochre,     sepia, more... ▸ Word origin ▸ Words similar to prehistoric ▸ Usage examples for prehistoric ▸ Idioms related to prehistoric ▸ Wikipedia articles (New!) ▸ Popular nouns described by prehistoric ▸ Words that often appear near prehistoric ▸ Rhymes of prehistoric ▸ Invented words related to prehistoric