Definition of dog day
1a dog days plural : the period between early July and early September when the hot sultry weather of summer usually occurs b : a day in dog days : a hot sultry day
2 dog days plural : a period marked by dull lack of progress the dog days following any major upheaval
Love words? You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.
Start your free trial today and get unlimited access to America's largest dictionary, with:
- More than 250,000 words that aren't in our free dictionary
- Expanded definitions, etymologies, and usage notes
- Advanced search features
- Ad free!
Origin and Etymology of dog day
back-formation from dog days, translation of Late Latin dies caniculares, translation of Greek hēmerai kynades; from their being reckoned in ancient times from the heliacal rising of the Dog Star (Sirius)
First Known Use: 1538See Words from the same year
Seen and Heard
What made you want to look up dog day? Please tell us where you read or heard it (including the quote, if possible).