Смысл:
a priori 
a priori[͵eıpraıʹɔ:raı,͵ɑ:prıʹɔ:ri:]
лат.
<Í> 1. априори; заранее; до опыта
to determine the value of smth. a priori - определять априорно ценность чего-л.
2. 1) априорный; доопытный
a priori reasoning - дедуктивное мышление
2) предположительный
PR Идиома
a lick and a promise
a hasty plan, a promise made without much thought If you get married on a lick and a a promise, you may need a lot of good luck.
a pretty penny
a lot of money, a high price I bet she paid a pretty penny for that coat. It looks expensive.
all spruced up
clean and dressed in your best clothes, dressed up The young farmers got all spruced up for the dance.
an ounce of prevention is worth a pound of cure
prevent a problem so you don't have to solve it, a stitch in time... Forest fires deserve an ounce of prevention: public education in campfire safety.
asking price
a starting price, a price to begin negotiations The asking price for the lot was $29,500. It sold for $28,000.
blow it out of proportion
exaggerate it, make it bigger than it should be When Gretzky was traded, the media blew it out of proportion.
break a promise
not do as you promised, go back on your word Trudy never breaks a promise. She is very dependable.
catch me by surprise
surprise me, not warn me The snowstorm in May caught us by surprise. We didn't expect it.
cool under pressure
calm during a crisis, able to perform well when you must do it Jo was very cool under pressure. When the judge asked questions, she answered clearly and calmly.
cooler heads prevailed
sensible people spoke, violence was avoided There was nearly a riot, but cooler heads prevailed.
cost a pretty penny
cost a lot of money, had a high price Elvis bought a new pink Cadillac. I bet that cost a pretty penny.
did yourself proud
did a good job, did well, did good, done good That was a great dinner, Nora. You did yourself proud.
do yourself proud
do something that you are proud of You did yourself proud when you helped the refugees.
get to the root of the problem
find the cause, get to the bottom of We got to the root of the problem. The children are afraid of the dog.
hard pressed
burdened with urgent business I am a little hard pressed for time. Can we meet later?
hot off the press
paper that has just been printed "As the boy handed me the paper he said, ""Hot off the press!"""
in your prime
during your best years, when you are strongest When he was in his prime, he played professional soccer.
keep a low profile
not go out much, lay low He plans to keep a low profile until the trial is over.
keep a promise
do what you promise to do You can depend on Vern to keep a promise. He's reliable.
lick and a promise
(See a lick and a promise)
make a good impression
meet and talk to strangers so they like you Penny made a good impression on my parents. She is so polite!
no problem (no prob)
it was not a problem, don't mention it """Thank you,"" I said. ""No problem,"" she replied."
on approval
taking a purchase home to decide if you want it I buy clothes on approval so I can return them if they don't fit.
on probation
becoming a permanent employee, proby As an employee on probation, you will be learning new skills.
ounce of prevention
(See an ounce of prevention)
pay the price
work hard, endure, suffer To be an Olympic athlete, you have to pay the price: pain.
play a prank on
arrange a surprise for you so people will laugh Ty played a prank on me. He left a message to call the President.
plug the product
(See put in a plug for)
PR
Public Relations With good PR the politician was able to easily gain the support of many people.
practice what you preach
do what you say people should do If you want to hear truth, tell the truth. Practice what you preach.
prairie oyster
the testicle of a young bull or bull calf Do you believe that some folks in Alberta eat prairie oysters?
praise him to the skies
praise him a lot, sing his praises Wade is an excellent student. His teachers praise him to the skies.
pre-menstrual syndrome
emotional crises the week before menstruation, pms Judy says pms causes most of her personal problems.
prepare like crazy
prepare thoroughly, be ready for an event or test Before I go to a job interview I prepare like crazy.
preppy
a youth who wears trendy clothes, clean cut Brad is a preppy. He wears Polo sweaters and drives a Celica.
presence of mind
ability to think clearly and act appropriately, cool under pressure When the bear charged the car, Jill had the presence of mind to sound the burglar alarm.
press charges
ask the police to charge someone with a crime The police asked her if she wanted to press charges against the thief.
press into service
required to help, forced to serve The young men were injured, so the old men were pressed into service.
press on
continue traveling, keep on going Dumont wanted to stop at Batoche, but he pressed on to Fort Carlton.
press (push) one
depend too much on luck, expect to continue to be lucky He is pushing his luck if he thinks that he will continue to make a lot of money on the stock market.
press the panic button
become very scared, panic, freak If a dog growls at me, I press the panic button. I scream and run.
pressed for time
have barely enough time He was pressed for time so I didn
pretty (adv.)
" rather; somewhat. "
pretty as a picture
very pretty, beautiful """How do I look in my new dress?"" ""Pretty as a picture, my dear."""
pretty penny
(See cost a pretty penny)
prey on (upon)
catch for food, kill and eat Cats usually prey on mice and small birds if they can catch them.
price out
check the price of, find out the price Before we buy a European car, we should price out parts and service.
price you have to pay
(See the price you have to pay)
prick
penis, dork, hoo-haw When the doctor asked me where it hurt, I pointed to my prick.
pride goeth before a fall
you lose self-respect before you do an evil deed Is this saying in the Bible? Pride goeth before a fall.