deterministic
adj.describing a system where the future is completely decided by the past. If you know all the starting conditions, you can predict exactly what will happen next.
adj.relating to a system in which the future state is entirely determined by the initial conditions and the laws of nature. Often used in contrast to probabilistic or stochastic systems.
“The computer program is deterministic, so it always gives the same result.”
“In a deterministic model, every input leads to exactly one output, making it easier to debug than a random process.”
“The philosopher argued that a deterministic universe leaves no room for free will, as every human action is the inevitable result of prior physical states.”
From determinist + -ic.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.