Caveat Emptor The principle that a person who buys something is responsible for making sure it works properly. Origin- new Latin, let the buyer beware; 1523 Sentence: It's still caveat emptor when is comes to calculating optional fees for baggage and other services.
Carte Blanche Permission to do something in any way you chose to do it. Origin- French, Literally, document; 1751 Sentence: We gave the decorator Carte Blanche to furnish the house.
Tete A Tete A private conversation between two people. Origin- French, Literally, Head to head; 1696 Sentence: Are you determined to cut shirt this pleasant tete a tete.
Pas De Deux A dance or figures for two performers. Origin- French, Literally, Step for two; Circa 1762 Sentence: I'm going to dance a pas de deux to Rachel's party.
Quid Pro Quo Something given or received for something else. Origin- new Latin, something for something; 1582. Sentence: If it helps us, he'll expect a quid pro quo.