full stop

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A period indicating the end of a sentence.
• noun A complete halt, as one made by a motor vehicle.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun UK, Australia, New Zealand, South Africa The punctuation mark “.” (indicating the end of a sentence or marking an abbreviation).
• interjection colloquial Used to emphasize the end of an important statement or point when speaking.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a punctuation mark (.) placed at the end of a declarative sentence to indicate a full stop or after abbreviations