abbrev

An abbreviation, abbreviated form, or abbrev, is a shortened representation of a word, phrase, or number. Abbreviations arise to save space, speed writing, or facilitate communication across languages. The term abbrev itself is an informal short form of abbreviation and is used in dictionaries and style discussions.

Abbreviations can be obtained by clipping (shortening a word), contraction (merging parts with an apostrophe), or by taking initial letters to form an acronym or an initialism. Acronyms are pronounced as a single word (NASA), while initialisms are spoken letter by letter (FBI). Other forms include symbols and measurement units (kg, lb).

Usage in formal writing typically follows a pattern: an abbreviation is introduced by the full form on first use, followed by the abbreviated form in parentheses, then used alone thereafter. Style guides vary on punctuation; some prefer periods after abbreviated letters (e.g., U.S., etc.), while others favor no periods. Capitalization rules depend on the source language and whether the form is a proper noun. In digital text, the HTML abbr element marks a word as an abbreviation and can supply the expansion via a title attribute.

History of abbreviations extends to ancient writing, with modern Western conventions expanding through the early modern period into standardized sets found in dictionaries and style guides. Abbreviations remain a practical tool in many fields, from academia to technology, balancing brevity with clarity.

Examples of common abbreviations include etc., e.g., i.e., Dr., Sr., PhD, DNA, AI, GPS. The term abbrev itself is widely used in discussions of language and typography.