We found 15 dictionaries that define the word thumbs down:

General (11 matching dictionaries)

1. thumbs-down, thumbs down: Merriam-Webster
2. thumbs-down: American Heritage Dictionary of the English Language
3. thumbs down: Collins English Dictionary
4. Thumbs-Down, Thumbs-down, thumbs-down: Wordnik
5. thumbs down: Cambridge Advanced Learner's Dictionary
6. thumbs-down, thumbs down: Wiktionary
7. thumbs-down: Infoplease Dictionary
8. thumbs-down, thumbs down: Dictionary.com
9. thumbs-down, thumbs down: TheFreeDictionary.com

Business (1 matching dictionary)

10. thumbs down: Legal dictionary

Computing (1 matching dictionary)

11. thumbs down: Encyclopedia

Medicine (1 matching dictionary)

12. thumbs down: Medical dictionary

Miscellaneous (1 matching dictionary)

13. thumbs down: Idioms

Definitions from Wiktionary (thumbs down) ▸ noun:  A gesture signifying disapproval; a thumb pointing down out of a fist. ▸ noun:  A rejection or refusal. Similar: thumbs-down, devil sign, donkey ears, down, throw-down, downdoot, downthrow, ding, digit, diss, more... Opposite: thumbs up, approval, endorsement, support Phrases: turn thumbs down, gave the thumbs down, give two thumbs down to, more... ▸ Words similar to thumbs down ▸ Usage examples for thumbs down ▸ Idioms related to thumbs down ▸ Wikipedia articles (New!) ▸ Words that often appear near thumbs down ▸ Rhymes of thumbs down ▸ Invented words related to thumbs down