from The American Heritage® Dictionary of the English Language, 4th Edition
- abbr. French répondez s'il vous plaît (please reply)
from Wiktionary, Creative Commons Attribution/Share-Alike License
- Initialism of reply please. (written on an invitation to request that the invited person reply to confirm whether or not they will be attending.)
- Initialism of Resource reservation protocol. (at Wikipedia)
- v. To reply to an invitation.
From the French RSVP, répondez s'il vous plaît, meaning “reply please”. (Wiktionary)