That is incapable of being measured. / That is incapable of being ascertained.

An indeterminable thing or quantity.

plural of indeterminable

The quality of being indeterminable.

Lack of determination; an unsettled or wavering state, as of the mind. / Lack of fixed or stated direction.

Not accurately determined or determinable. / Imprecise or vague.

(algebra, strict sense) A symbol that resembles a variable or parameter but is used purely formally and neither signifies nor is ever assigned a particular value; / (loose sense) a variable.

not accurately determined or determinable / imprecise or vague

(mathematics) A variable with no value assigned to it; for example the variables in a polynomial.

plural of indeterminate