determinative

Short definition from Wiktionary

Noun

1. 1
   An ideogram used to mark semantic categories of words in logographic scripts.
2. 2
   A member of a class of words functioning in a noun phrase to identify or distinguish a referent without describing or modifying it.

Adjective

1. 1
   That determines something.
2. 2
   Sufficient to decide something (such as a question of fact or of law).