indeterminate

Not precisely determined or established; not fixed or known in advance.

“of indeterminate age”

“a zillion is a large indeterminate number”

Having a capacity for continuing to grow at the apex.

“an indeterminate stem”

Not leading to a definite ending or result.

“an indeterminate campaign”

(of a quantity) having no definite value, as an equation that cannot be solved.

“0/0 is an indeterminate form”

Of uncertain or ambiguous nature.

“the equivocal (or indeterminate) objects painted by surrealists”