(military) Of a fortress or other fortified place: able to withstand all attacks; impenetrable, inconquerable, unvanquishable. / (figuratively) Too strong to be defeated or overcome; invincible.

Capable of being impregnated; impregnatable.

The state of being impregnable; impregnability.

plural of impregnation

(obsolete) That which impregnates.

(obsolete) Not pregnant; unfertilized or infertile.

Third-person singular simple present indicative form of impregnate

(transitive) To cause to become pregnant. / (transitive) To fertilize. / (transitive) To saturate, or infuse. / (transitive) To fill pores or spaces with a substance.

The act of making pregnant; fertilization. / The fact or process of imbuing or saturating with something; diffusion of some element, idea etc. through a medium or substance.

The quality or state of being impregnable; invincibility.