What does it mean
Name that Idiom
What does it mean 2
challenge
what does it mean 3
100

Piece of cake

that was easy

100

to joke or tease

pull someone's leg

100

A little birdie told me

someone told you a secret

100

at the drop of a hat 

to do something right away

100

hit the books

study very seriously

200

Break a leg

Good luck

200

i'm not feeling well

under the weather

200

slipped my mind

I forgot, I did not remember

200

apple of my eye

to cherish or prize something or someone above all else

200

things would look up

things would improve

300

sleep on it

i'm going to think about it

300

to reveal a secret

to spill the beans

300

hold your horses

wait a minute, slow down

300

take the bull by the horns

to tackle or go after something hard or challenging

300

make your move

take action

400

out of the blue

completely unexpected; out of no where 
400

i'm listening to you 

i'm all ears

400

in hot water

to be in trouble

400

time is money

time is valuable, do not waster your time

400

turn over a new leaf

to change for the better

500

when pigs fly

it's never going to happen

500

someone stays up late working hard

to burn the midnight oil

500

once in a blue moon

something that happens very rarely

500

beat around the bush

avoid a subject or question by talking about topics not related to subject or question

500

hit the nail on the head

to be exactly right