There's No Such Thing as a Free Lunch:

In the 1840s, bars in the United States offered anyone buying a drink a "free lunch." It was really just a bunch of salty snacks that made customers so thirsty, they kept buying drinks.

The Big Cheese:

In 1802, a cheesemaker delivered a 1,235-pound wheel of cheese to President Thomas Jefferson. Citizens referred to both the wheel and its important recipient as the "big cheese."

Cool as a Cucumber:

Even on a warm day, a field cucumber stays about 20 degrees cooler than the outside air. Though scientists didn't prove this until 1970, the saying has been around since the early 18th century.

Bring Home the Bacon:

The Dunmow Flitch Trials, an English tradition that started in 1104, challenged married couples to go one year without arguing. The winners took home a "flitch" (a side) of bacon.

Spill the Beans:

In ancient Greece, the system for voting new members into a private club involved secretly placing colored beans into opaque jars. Prospective members never knew who voted for or against them—unless the beans were spilled.

Gone to Pot:

Dating to pre-Elizabethan England, this phrase refers to hardened pieces of meat that were on the verge of spoiling—and good only for the stew pot.

Easy as Pie:

Making a pie from scratch isn't easy; the phrase is a contraction of the late-19th-century phrase "easy as eating pie."

In a Pickle:

From the old Dutch phrase "de pikel zitten," which means to sit in a salt solution used for preserving pickles sure to be an uncomfortable situation.

With a Grain of Salt:

To take something "with a grain of salt" is to consider the subject with skepticism or suspicion. Salt was once believed to have healing properties, and to eat or drink something with a grain of salt was to practice preventive medicine against potential poisoning or illness.

Happy as a Clam:

The original phrase was "happy as a clam at high tide." Because clam diggers are able to gather clams only at low tide, the clams are much safer (and happier) when the tide is high and the water is too deep to wade into.

Take the Cake:

The phrase originated at cakewalk contests, where individuals would parade and prance in a circle to the audience's delight. The person with the most imaginative swagger would take home first prize, which was always a cake.

A Baker's Dozen:

It was once common that English medieval bakers would cut corners and dupe customers by making loaves that contained more air pockets than bread. By 1266, authorities enacted a law that required bakers to sell their bread by weight. To avoid paying the heavy penalties, bakers started adding an extra loaf for every dozen: hence the number 13.