an article, as English a, an, that denotes class membership of the noun it modifies without particularizing it.
Origin
1720-30
Examples from the web for indefinite article
If the noun has the indefinite article the infinitive is better sometimes.
The control over the definite and indefinite article is examined in relation to their forms and functions.
Use the indefinite article an before abbreviations and acronyms that are pronounced as if they begin with a vowel.
The simple addition of the indefinite article a eliminates the ambiguity.
The word following the indefinite article begins with a vowel sound.
British Dictionary definitions for indefinite article
indefinite article
noun
1.
(grammar) a determiner that expresses nonspecificity of reference, such as a, an, or someCompare definite article
indefinite article in Culture
indefinite article definition
The word a or an introducing an unspecified noun or the name of a general category: “a dog,” “an apple,” “an orange.” An is used when the next word begins with a vowel or a silent (unpronounced) h, as in “an egg” or “an hour.”