determiner

/D IH0 T ER1 M IH0 N ER0/
noun
  1. 1

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

  2. 2

    (grammar) A dependent function in a noun phrase marking the NP 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.

  3. 3

    Something that determines, or helps someone to determine, something else.

Source: https://en.wiktionary.org/wiki/determiner