Animals
"It's raining cats and dogs"
It is raining very hard.
"Piece of cake"
"Break a leg"
"Once in a blue moon"
Rarely
"Under the weather"
Sick
Let the cat out of the bag
To tell a secret
"Spill the beans"
Tell a secret
"Keep an eye on"
To watch
"Green with envy"
Jealous
"Hit the hay"
Go to sleep
"Hold your horses"
Wait a moment
"Cool as a cucumber"
Very calm.
"Cost an arm and a leg"
Very expensive
"Out of the blue"
Suddenly, Unexpected
"On cloud nine"
Very happy
"The early bird catches the worm"
People who wake up early or act first get advantages.
"Butterflies in my stomach"
Feeling nervous.
"By the skin of your teeth"
"See red"
to be angry
"The tip of the iceberg"
A small part of a bigger problem.
"A fish out of water"
Someone who feels uncomfortable in a new situation.
"Eat like a bird"
Eat very little
"Head over heels"
In love
"White lie"
A small, harmless lie
"Barking up the wrong tree"
Making a wrong assumption.