Complex sentence: An article (with the linguistic glossing abbreviation) is a word that is used alongside a noun (as a standalone word or a prefix or suffix) to specify grammatical definiteness of the noun, and in some languages extending to volume or numerical scope.
Split into simpler sentences: An article (abbreviated to) is a word that is used alongside a noun (prefix or suffix) to indicate the type of reference being made by the noun. Articles specify grammatical definiteness of the noun, in some languages extending to volume or numerical scope.