The modern subject is the subject of the sciences.

to hit the hay_go to bed

it's brass monkeys_It's freezing cold

to rustle up_to make or find something quickly for somebody and without planning

to swing by_to visit a place or person for a short time

to lose your rag_get angry

a red herring_a false clue

endeavour_an attempt to do something, especially something new or difficult

monkey business_dishonest or silly behaviour

to be as nice as pie_very kind and friendly, especially when you are not expecting it

to feel giddy_dizzy

a handful_a person or an animal that is difficult to control

a skeleton in the cupboard_something shocking, embarrassing, etc. That has happened to you or your family in the past that you want to keep secret

let sleeping dogs lie_to avoid mentioning a subject or something that happened in the past, in order to avoid any problems or arguments

to be nuts_crazy

to poke your nose into sth_To try to become involved in something that does not concern you

The apple of her eye_one that is treasured

a pig of a day_a bad day

stone dead_This idiom is a way of emphasizing that there were absolutely no signs of life or movement.

to knock the living daylights out of someone_hit sb hard

mad as a hatter_to be completely crazy

to laugh your socks off_to laugh very loudly and for a long time