-- Meaning of A idiom --

A1
In a high quality, in a good order.

A is one thing, B is another
Two things which seem to be the same are actually different

A hot potato
A hot issue that people are talking about

A man of sense
Someone who has a good heart

A penny for your thoughts
Ask someone about their thoughts

A piece of cake            
Something very easy    

ABC
Refer to something or someone that in the very beginning step.

About to
Almost ready to

Above someone's head
Too hard for someone to understand.

Acid Test
A hard way to prove sincerity of someone/ something.

Across the board
Totally agree or applicable with no condition.

Act of God
An incident occured by nature with zero humans involement.

Add insult to injury
Make a bad situation even worse

Ad hoc
Something unplanned. Not happen regularly.

All fingers and thumbs
Very clumsy.

All square
Even. Mission complete.

All thumbs
Clumsy, do things in an awkward way

An eye for an eye
React in the same level. Usually in negative way

Anchor man/ anchor woman
An important person in a group.

Anything but....
Anything except...

Apple of one's eyes
One's most favoriate among the others.

Around the clock
All day all night

As a last resort
Last choice. The last thing one would do if no other option

At full length
From the start to the end. From one edge to another

At one blow
At one hit

At stake
At risk, risky