The term "indeterminate" is sometimes used as a synonym for unknown or variable (Becker and Weispfenning 1993, p. 188).
A mathematical expression can also be said to be indeterminate if it is not definitively or precisely determined. A standard calculus use of the term occurs in an indeterminate form of a limit.
The Wolfram Language returns the symbol Indeterminate
upon encountering an indeterminate expression in the course of an evaluation. For
example, the expression 
is indeterminate because the two infinite quantities can approach infinity at rates
whose difference has different limiting behavior. This differs from an undefined
expression, for which no value is assigned in the relevant context.
The Wolfram Functions Site uses the notation > to represent an indeterminate quantity.
