Definition of "determiner"

(grammar) A member of a class of words functioning in a noun phrase to identify or distinguish a referent without describing or modifying it.  examples

(grammar) A dependent function in a noun phrase that marks it as definite or indefinite. This function is usually filled by words in the determinative class but may be filled by other elements such as a genitive pronoun.  examples

Something (some input factor, a nonsentient agent) that determines, or helps someone to determine, something else.  quotations  examples

Someone (a sentient agent) who determines; a decider of a disposition.  examples