indefinite article(n = noun.communication) - a determiner (as `a' or `some' in English) that indicates nonspecific reference;
is a kind of article

article, article of clothing, article of commerce, article of faith, article of furniture, definite article, feature article, indefinite, indefinite integral, indefinite quantity, large indefinite amount, large indefinite quantity, magazine article, news article, newspaper article, review article, small indefinite amount, small indefinite quantity, toilet article