Idioms

About time:
Nearly time, high time. "It's about time you bought a new car!"

Absence makes the heart grow fonder:
Proverb that means that our feeling for those we love increases when we are apart from them.

(To) act high and mighty:
To act proudly and arrogantly.

Actions speak louder than words:
Proverb meaning that's it's better to do something about a problem than to talk about it.

(To) act one's age:
To behave in a more mature way. Frequently said to a child or teen. ex. "Bill, stop throwing rocks! Act your age!"

(To) add fuel to the fire:
To make a bad problem even worse.

(To) add insult to injury:
To make a bad situation even worse.

Against the clock:
To attempt to do something "against the clock" is to attempt to do something as fast as possible usually before a deadline.

All-out:
Complete. Very strong. "They did an all-out search for the missing boy and they found him."

All set:
Ready (to go). "All set?"

All thumbs:
Awkward. Clumsy.

A little bird told me:
When someone says "a little bird told me" it means they don't want you to know who told them.

All in a day's work:
Typical. Normal. Expected. ex. "Talking to famous celebrities is all in a day's work for some Hollywood reporters."

(From) all walks of life:
(From) all social, economic, and ethnic groups. ex. "People from all walks of life voted for him, but he still lost the presidential election."

Apple of someone's eye:
Someone's favorite person (and sometimes thing). ex. "Sarah was the apple of Tom's eye for quite a long time. He was very much in love with her."

Armed to the teeth:
Heavily armed. ex. "The rebels were armed to the teeth."

At all hours (of the night):
Very late at night, throughout the night. ex. "Her boyfriend would call her at all hours of the night."

At each other's throats:
Fighting or arguing heavily. ex. "They were at each other's throats. The arguments never stopped."

At this stage:
At this point. ex. "At this stage, it's difficult to say who will win the election."