indeterminant

Indeterminant is an adjective describing something that cannot be determined or fixed by the information available, rules governing it, or prior conditions. In everyday and technical usage, it signals uncertainty, variability, or a lack of a unique value. The preferred and more common term in most disciplines is indeterminate, but indeterminant appears as a variant in some texts.

In mathematics, indeterminate forms arise in limits when the form alone does not determine the limit’s value. Classic examples such as 0/0 or ∞/∞ require further analysis—through algebraic manipulation, L’Hôpital’s rule, or other techniques—to resolve the actual limit. The broader idea is that the information given by the expression’s form is insufficient to yield a single answer without additional work.

In science and philosophy, indeterminacy or indeterminism describes situations where outcomes cannot be predicted precisely from prior conditions. In physics, quantum mechanics is often described as having intrinsic indeterminacy in certain properties before measurement. In philosophy and linguistics, indeterminacy can refer to vagueness, multiple possible interpretations, or events not fixed by laws alone.

Terminology note: indeterminant is less common than indeterminate or indeterminacy in formal writing. Some sources treat indeterminant as a valid variant, but readers should be aware that most standard references prefer the other forms.

See also: indeterminate, indeterminacy, indeterminacy (quantum mechanics), nondeterminism.