We found 10 dictionaries that define the word dull as dishwater:

General (5 matching dictionaries)

1. (as) dull as dishwater, dull as dishwater: Merriam-Webster
2. dull as dishwater: Oxford Learner's Dictionaries
3. dull as dishwater: Wiktionary
4. dull as dishwater: Dictionary.com
5. dull as dishwater: TheFreeDictionary.com

Business (1 matching dictionary)

6. dull as dishwater: Legal dictionary

Computing (1 matching dictionary)

7. dull as dishwater: Encyclopedia

Medicine (1 matching dictionary)

8. dull as dishwater: Medical dictionary

Miscellaneous (1 matching dictionary)

9. dull as dishwater: Idioms

Slang (1 matching dictionary)

10. dull as dishwater: English slang and colloquialisms used in the United Kingdom

Definitions from Wiktionary (dull as dishwater) ▸ adjective:  (simile) Boring; ordinary; exceedingly dull. Similar: dullsome, sameish, soporific, dull, ponderous, like a bowl in a china shop, dragging, banal, dullish, dreich, more... Phrases: as dull as dishwater, more... ▸ Words similar to dull as dishwater ▸ Usage examples for dull as dishwater ▸ Idioms related to dull as dishwater ▸ Wikipedia articles (New!) ▸ Popular nouns described by dull as dishwater ▸ Words that often appear near dull as dishwater ▸ Rhymes of dull as dishwater ▸ Invented words related to dull as dishwater