Adjective

(en adjective)

of, or relating to determinism

(mathematics, of a Turing machine) having at most one instruction associated with any given internal state

(physics, of a system) Having exactly predictable time evolution.

(computing, of an algorithm) Having each state depend only on the immediately previous state, as opposed to having some states depend on backtracking where there may be multiple possible next actions and no way to choose between them except by trying each one and backtracking upon failure.

Adjective

(en adjective)

Having the power or quality of deciding a question or controversy; putting an end to contest or controversy; final; conclusive.

''A decisive battle is fatal for one side's war chances

* {{quote-news

, year=2011 , date=November 3 , author=Chris Bevan , title=Rubin Kazan 1 - 0 Tottenham , work=BBC Sport citation , page= , passage=In truth, Tottenham never really looked like taking all three points and this defeat means they face a battle to reach the knockout stages -with their next home game against PAOK Salonika on 30 November likely to prove decisive .}}

Marked by promptness and decision.

A noble instance of this attribute of the decisive character. -J. Foster.