Can you name the musical whose long run on Broadway ended two years ago today? Here's a hint: Its more than 7,400 performances calls to mind a proverb about long-living felines.

That's right: Cats ended its 18-year run two years, and although it may last another nine lives in repertory, today we pay tribute to its longevity with a look at a pair of similarly long-lasting cat terms.

The hardiness and tenacity of felines inspired the phrase "a cat has nine lives", but cats' characteristics have inspired other adages too. French, German, and Russian speakers all have their own version of the English observation, "When the cat's away the mice will play."

We can thank the Irish—or perhaps the Hessian soldiers occupying the Irish town of Kilkenny—for coming up with the phrase, "fighting like Kilkenny cats" to mean "fighting until both sides have lost or are destroyed." As the story goes, during the Irish rebellion of 1798, the occupying troops amused themselves by tying two cats together by their tails. When an officer approached to stop the torture, one soldier lopped off the two tails with his sword and the cats fled. Challenged to explain the two bloody tails, the soldier claimed the cats had been fighting and devoured each other, except for their tails.