To rain very heavily.

What is "To rain cats and dogs".
To wish someone good luck.

Break a leg.
Something that is very easy to do.

A piece of cake.
Give someone permission to do something.

To give a green light.
To do something just to pass time.
What is "To kill time."
To create a new set of problems
To open a can of worms.
To stop talking and be quiet.

Zip your lips
Of bad quality or in bad taste.

Cheesy
An innocent lie used to protect someone's feelings.

A white lie
When time passes really quickly.

What is "Time flies."
To be extremely busy

Busy as a bee
To listen carefully.
To be all ears
To go crazy or mad.

Go bananas.
Very jealous.

Green with envy.
When something takes place repeatedly, every once in a while.

What is "Time after time."
To get two things done at once.

What is "To kill two birds with one stone."
Someone or something that is very annoying.

A pain in the neck.
Someone who is very calm.

Cool as a cucumber.
Very unexpectedly.

Out of the blue.
To not waste time because it is a valuable resource.

What is "Time is money."
To reveal a secret.

"To let the cat out of the bag."
Extremely quickly.
In the blink of an eye.
Someone I love, adore and admire.

The apple of my eye.
To get caught doing something wrong, illegal, or unlawful.
Caught red handed.
A situation where something must be done quickly before it is too late.
What is "Around the clock."