Animal idioms
Let the cat out of the bag
to reveal a secret
A piece of cake
a job, task, or other activity that is easy or simple
Cost an arm and a leg
very expensive, a lot of money
Have a ball
enjoy one's self, have a good time
Put yourself in one's shoes
to see something from another person's point of view, to have empathy
To smell a rat
to sense that something is wrong about a situation
At the drop of a hat
without any hesitation; instantly
Best thing since sliced bread
a really good plan, product, idea or innovation
Splurge
spend a lot of money for something
Wear the trousers
To be the leader, to be in charge
Let sleeping dogs lie
to ignore a problem because trying to deal with it could cause an even more difficult situation
Can't judge a book by its cover
Pick up the tab
Tighten one's belt
spend less money than before
Have other bigger fish to fry
to have other more important or interesting things to do
A hot potato
Something current which many people are talking about and which is usually disagreed on
Jump on the bandwagon
to join in with what everyone else is doing, something popular
Treat
pay for someone else
Under one's hat
to keep a secret, not to mention it
A bee in your bonnet
to talk and think a lot about something
Cut corners
when something is done badly, often to save money
Cut the mustard
Succeed, meet expectations, behave adequately
Freeload
get things that others pay for
Keep one's shirt on
not to overreact, to be calm