sick as a dog
Proposed by a contributor, not yet supported by evidence.
Meaning · English
Very ill.
Where it’s used:
Used
American English
Examples
I caught that new strain of flu and for three days I was as sick as a dog.
Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30)
Sources & notes
Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30 via kaikki.org). Figurative class: Simile (PIE-English corpus, CC BY 4.0, retrieved 2026-07-31).
Common questions
What does “sick as a dog” mean?
Very ill.
Is “sick as a dog” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.