We found 18 dictionaries that define the word thumb's up:

General (13 matching dictionaries)

1. thumbs-up: Merriam-Webster
2. thumbs up: Oxford Learner's Dictionaries
3. thumbs-up: American Heritage Dictionary of the English Language
4. thumbs up: Collins English Dictionary
5. Thumbs-Up, Thumbs-up, thumbs-up: Wordnik
6. thumbs up: Cambridge Advanced Learner's Dictionary
7. thumbs-up, thumbs up: Wiktionary
8. thumbs-up: Infoplease Dictionary
9. thumbs-up, thumbs up: Dictionary.com
10. Thumbs Up (EP), Thumbs Up (disambiguation), Thumbs Up (film), Thumbs Up (newspaper), Thumbs Up, Thumbs-up, Thumbs up (gesture), Thumbs up: Wikipedia, the Free Encyclopedia
11. thumbs-up, thumbs up: TheFreeDictionary.com

Business (1 matching dictionary)

12. thumbs up: Legal dictionary

Computing (1 matching dictionary)

13. thumbs up: Encyclopedia

Medicine (1 matching dictionary)

14. thumbs up: Medical dictionary

Miscellaneous (1 matching dictionary)

15. thumbs up: Idioms

Slang (1 matching dictionary)

16. Thumbs-up: Urban Dictionary

Definitions from Wiktionary (Thumb's up) ▸ noun:  Misspelling of thumbs up. [A gesture signifying approval or okay; a thumb pointing up out of a fist.] Similar: thumb's up, V sign, tick, fist, point, thumbmark, shaka, peace sign, high sign, V-sign, more... Opposite: thumbs down, disapproval, rejection, negative, response Phrases: two thumbs up, more... Adjectives: handholding, bob, windup, backhand, beat, ticky, tappy, wind-up, gripple, clutch, strut ▸ Words similar to thumb's up ▸ Usage examples for thumb's up ▸ Idioms related to thumb's up ▸ Wikipedia articles (New!) ▸ Words that often appear near thumb's up ▸ Rhymes of thumb's up ▸ Invented words related to thumb's up