1) Weasel Out-to squeeze one's way out of something, to evade or avoid a job or responsibility-
Although they had signed the contract they tried to weasel out of the deal later.
2) Beat Head Against The Wall-to do, say, or ask for something repeatedly but to be unable to change a situation-
I keep asking her not to park there, but it's like banging my head against a brick wall.
3) The Gift Of The Gab-the ability to speak easily and confidently in a way that makes people want to listen to you and believe you-She's got the gift of the gab -
she should work in sales and marketing.
4) The Devil Is In The Details-used for saying that something may seem simple, but in fact the details are complicated and likely to cause problems-
The Irish economy is performing strongly, but the devil is in the detail.
5) Nip Something In The Bud-to stop something before it has an opportunity to become established-
Many serious illnesses can be nipped in the bud if they are detected early enough.
6) Go Off The Rails-to start behaving in a way that is not generally acceptable, especially dishonestly or illegally-
He went off the rails in his first year at university.
7) Make Believe-believing or imagining things that appear to be attractive or exciting, but are not real-
The ideal of a perfectly fair society is just make-believe.
8) Fool's Errand-a task or activity that has no hope of success-
It is a fool's errand trying to get Lena to join in anything.
9) Play Fast And Loose-to treat something or someone without enough care-
Like many movie-makers, he plays fast and loose with the facts to tell his own version of the story.
10) Putty In Someone's Hands-easily influenced by someone else, excessively willing to do what someone else wishes-
As soon as Jones realized he could get in trouble if they reported him, he became putty in their hands.
11) Pass Muster-be accepted as adequate or satisfactory-
This manifesto would not pass muster with the voters.
12) Stick To Your Guns-to continue to have your beliefs or continue with a plan of action, even if other people disagree with you-
Despite harsh criticism, she's sticking to her guns on this issue.
13) Red Herring-a fact, idea, or subject that takes people's attention away from the central point being considered-
The police investigated many clues, but they were all red herrings.
14) Go All Round The Houses-to say or do something in a very complicated way when it could be very simple-
There's no need to go all round the houses, just tell me straight out what's wrong.
15) Just What The Doctor Ordered-exactly what is wanted or needed-
Thanks, a strong cup of coffee in the morning is just what the doctor ordered.
16) Kangaroo Court-an unofficial court or a court that disregards current laws and conducts unfair trials-
People who live under oppressive regimes are often treated harshly by corrupt kangaroo courts that don't abide by the law.
17) Leave To Own Devices-to let someone do what they want without helping/controlling them-
There are four hours of lessons each morning, and in the afternoon students are left to their own devices.
18) Way The Wind Blows-information about a situation, especially other people's opinions-
I think I'll see which way the wind is blowing before I vote at the board meeting.
19) Cast A Shadow Over-to spoil a good situation with something unpleasant, to have influence over something-
Her father's illness had cast a shadow over the birth of her baby.
20) Pick Someone's Brain-to ask someone's advice about a subject the person knows a lot about-
Can I pick your brain about how you got rid of those weeds?