R.S.V.P. comes from the French phrase, 'répondez, s'il vous plaît,' which means 'please reply.' According to western etiquette, you should reply promptly if you receive a formal invitation.
More Language Facts
One thousand contains the letter A, but none of the words from one to nine hundred ninety-nine has an A.
Skepticisms is the longest word that alternates hands when typing.
The word four has four letters. In the English language there is no other number whose number of letters is equal to its value.