An idiom is a group of words in a fixed order and the meaning of which cannot be derived from the individual words. All the words must be put together for its special meaning to be determined...

Example:
The student wanted to throw dust into our eyes.

The above statement means the student wanted to deceive us.

An idiomatic expression is a word made up of a preposition and a verb with a fixed meaning.

Example:
The rich man has passed on.

The expression 'has passed on' consist of a verb and a preposition. It is, therefore, an idiomatic expression.


SOME IDIOMS AND THEIR MEANINGS 
1. A cock and a bull story= an incredible or unbelievable story.
2.An eye for an eye= revenge, retaliation
3.A hard nut to crack= a difficult person
4.A Good Samaritan= a kind person who helps another person in distress.
5.Give up the ghost= die
6.Get on one's nerves= irritate
7.Eat one's word= withdraw something said earlier
8.Blow one's own trumpet= boast or brag
9.Get into hot water= get into trouble
10.Be born with a silver spoon in the mouth= to be born into a rich home

SOME IDIOMATIC EXPRESSIONS AND THEIR MEANINGS 
1.Step in--- intervene to help or prevent
2.Pass on ---die
3.Own up--- confess or admit
4.Polish up --- improve
5.Look into--- investigate or research something
6.Give away--- betray
7.iron out ---- solve or resolve a prob or issue
8.Give up---- surrender ; admit defeat
9.Come off--- take place
10.Count on---- rely on.


Please do more research and learn the other one's as well....


EXERCISE 
Select the best option that is similar in meaning to the underlined group of words.

1. Araba's visit was *a bolt from the blue* . This means that the visit was....
A. a most welcome one
B. short
C. a complete surprise
D. timely

2.My uncle loves to cast his bread upon the waters.This means that my uncle
A. Behaves strangely
B.feeds his fish with bread
C.is wasteful
D.loves to help people

3.When he lost his job, Yaro was left sink or swim. This means that Yaro
A. was depressed
B.shouted for help
C.hand to find another job
D.had to survive on his own.

4. I was informed at the eleventh hour about his decision to leave. This means that I heard about his decision
A. immediately
B.very late
C.in good time
D.at eleven o'clock

5.John had to eat his words when our team won the match. This means that John
A.became very much surprised
B.admitted he was wrong
C.denied all that he had said
D.lost appetite.