Webster's Revised Unabridged Dictionary · 1913

Determinative

Determinative , adjective

[Compare French déterminatif.]

Having power to determine; limiting; shaping; directing; conclusive.
Incidents... determinative of their course. — I. Taylor
Collocations (1)
Determinative tables (Nat. Hist.) , tables presenting the specific character of minerals, plants, etc., to assist in determining the species to which a specimen belongs.

Determinative , noun

That which serves to determine.
Explanatory determinatives... were placed after words phonetically expressed, in order to serve as an aid to the reader in determining the meaning. — I. Taylor (The Alphabet)