Unimpregnated
Unimpregnated refers to a state of not being filled or permeated with a substance. In a biological context, unimpregnated is most commonly used to describe a female animal or human who has not conceived or become pregnant. This can be a natural state or the result of medical intervention. It implies the absence of fertilization of an egg or the implantation of an embryo.
The term can also be applied in material science. For instance, an unimpregnated fabric or porous material