Period
The full point, full stop (British and broader Commonwealth English) or period (North American English) is a punctuation mark. It is used for several purposes, the most frequent of which is to mark the end of a declaratory sentence (as opposed to a question or exclamation); this sentence-terminal use is properly, or the precise meaning of, full stop.
The full stop is also often used alone to indicate omitted characters (or in an ellipsis, "..." to indicate omitted words). It may be placed after an initial letter used to stand for a name, or sometimes after each individual letter in an initialism or acronym, for example, "U.S.A."; however, this style is declining, and many initialisms like UK or NATO have individually become accepted norms. A full stop is also frequently used at the end of word abbreviations – in British usage, primarily truncations like Rev., but not after contractions like Revd; however, in American English it is used in both cases.