We found 22 dictionaries that define the word thickhead:

General (17 matching dictionaries)

1. thickhead: Merriam-Webster
2. thickhead: Oxford Learner's Dictionaries
3. thickhead: American Heritage Dictionary of the English Language
4. thickhead: Collins English Dictionary
5. thickhead: Vocabulary.com
6. thickhead: Wordnik
7. thickhead: Wiktionary
8. thickhead: Webster's New World College Dictionary, 4th Ed.
9. thickhead: Infoplease Dictionary
10. thickhead: Dictionary.com
11. Thickhead: Online Plain Text English Dictionary
12. thickhead: Webster's Revised Unabridged, 1913 Edition
13. thickhead: Rhymezone
14. Thickhead: AllWords.com Multi-Lingual Dictionary
15. thickhead: FreeDictionary.org
16. thickhead: Mnemonic Dictionary
17. thickhead: TheFreeDictionary.com

Business (1 matching dictionary)

18. thickhead: Legal dictionary

Computing (1 matching dictionary)

19. thickhead: Encyclopedia

Medicine (1 matching dictionary)

20. online medical dictionary (No longer online)

Slang (2 matching dictionaries)

21. thickhead: Green’s Dictionary of Slang
22. thickhead: Urban Dictionary

(Note: See thickheads as well.)

Definitions from Wiktionary (thickhead) ▸ noun:  Someone stupid. ▸ noun:  Any of several species of Australian songbirds of the genus Pachycephala. Similar: whistler, thickwit, thick, thicko, thickie, dumbhead, thickskull, thicky, stupid-head, nuthead, more... Opposite: quick-witted, sharp, intelligent, clever Phrases: white-throated thickhead, white throated thickhead, more... ▸ Words similar to thickhead ▸ Usage examples for thickhead ▸ Idioms related to thickhead ▸ Wikipedia articles (New!) ▸ Popular adjectives describing thickhead ▸ Words that often appear near thickhead ▸ Rhymes of thickhead ▸ Invented words related to thickhead