Definition of impregnable

The word "impregnable" comes from the Latin word impregnābilis, which literally means "not able to be impregnated." In medieval times, when many fortified structures were built, the term was applied not just to women, but also to castles and other fortifications. It signified that these structures were so well-fortified that enemy armies would be unable to capture them, just as a pregnant female cannot easily repel a baby trying to enter her body. The origin of the word in this context highlights the symbolic connection between fortifications and the human body. Just as armies sought to breach the imposing walls of fortifications, babies attempted to penetrate the barrier of a mother's womb. Both scenarios involved applying force to overcome the barrier's defenses. Therefore, calling a fortification "impregnable" was a way of expressing its strength and impenetrability.