If you say, ''The cat's out of the bag'' instead of ''The secret is given away,'' you're using an idiom. The meaning of idiom is different from the actual meaning of the words used. ''An apple a day keeps the doctor away'' is proverb. Proverbs are old but familiar saying that usually give advice. Both idioms and proverbs are part of our daily speech. Many are very old and have interesting histories. See how many of these saying you know?

''An apple a day keeps the doctor away.''

This proverb comes from the ancient Romans, who believed the apple had magical powers to cure illness. In fact, apples are filled with vitamin C, protein, pectin, natural sugars, copper and iron. They do promote health.

''Saved by the bell.''

In the 17th-century England, a guard at Windsor Castle was accused of falling asleep at his post. He claimed he was wrongly accused and could prove it; he had heard the church bell chime 12 times at midnight.

Townspeople supported his claim and he was not executed. Today we think of the bell that ends a round in boxing, often saving the boxer from injury, or the bell at the end of a class period, saving you from more work. Regardless, this idiom means rescue from a situation at the last possible moment.

''Bury the hatchet.''

Native Americans used to bury weapons to show that fighting had ended and enemies were now at peace. Today, the idiom means to make up with a friend after an argument or fight.

''Dot the i's and cross the t's.''

When only handwritten documents were used, it was very important for the clerk to write everything properly, especially letters like i and t, which could easily be confused. The idiom has since come to mean paying attention to every little detail.

''Raining cats and dogs.''

In Norse mythology, the dog is associated with wind and the cat with storms. This expression means it's raining very heavily.

''To shed crocodile tears.''

Crocodiles have a reflex that causes their eyes to tear when they open their mouths. This makes it look as though they are crying while devouring their prey. In fact, neither crocodiles nor people who shed ''crocodile'' tears feel sorry for their actions.

(Courtesy ***Saudi Gazette***)