dogdays

Noun

dog days pl (normally plural, singular dog day)

1. (archaic, plural, plural-normally) The days following the heliacal rising of Sirius, now in early August (Gregorian) at dates varying by latitude.
   • ... a sterre, wherof canicular or dogge days be named Dies caniculares.1538, Thomas Elyot, “Canicula”, in The Dictionary of Syr Thomas Eliot

   Synonyms:

   canicular days

2. (plural, plural-normally) The unpleasantly hot days of late summer.
   • Why ſhould thoſe Eteſian and Eaſterne winds blow cōtinually in ſome places, at ſet times, one way ſtill, in the dog dayes only: heere perpetuall drought, there dropping ſhowres; [...]1624, Democritus Junior [pseudonym; Robert Burton], “Ayre Rectified. With a Digression of the Ayre.”, in The Anatomy of Melancholy: […], 2nd edition, Oxford, Oxfordshire: […] John Lichfield and James...
3. (plural, plural-normally) Any similar period of inactivity, laziness, or stagnation.
   • The two-cassette miniseries, produced by Oliver Stone, arrives in early August, in time to stir the dog days of summer rentals.1993, Billboard, volume 105, number 24, page 62