Meaning of dog days

dog' days"

Pronunciation: [key]
  1. the sultry part of the summer, supposed to occur during the period that Sirius, the Dog Star, rises at the same time as the sun: now often reckoned from July 3 to August 11.
  2. a period marked by lethargy, inactivity, or indolence.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.