Here are some phrases that were once in common use, along with their definitions.
1. Bee’s knees — means the height of perfection. (Also, “the cat’s pajamas,” “the cat’s meow.”) The phrase originated in the late 1700s to describe something insignificant; however, in the 1920s, it came to mean the opposite, according to the Oxford Dictionaries. Example:
I love Matthew Inman’s latest comic; it’s the bee’s knees.
2. At sixes and sevens — means in a state of confusion or disarray. Phrase came from the numbers on dice and cards. To gamble on these numbers was considered reckless. Example:
These schedule changes have employees at sixes and sevens.
3. Dog days — refers to the beginning of July to mid-August to coincide with the rising of Sirius, the brightest star in the constellation Canis Major. This is also the hottest period of summer. Example:
In sweltering Austin, it feels like the dog days last all summer.