Impregnable is an adjective that means incapable of being taken or conquered.

Coming from a Middle French word that means ‘to take or capture,’ our word of the day took life by adding the prefix I-M, meaning ‘not’ and forming impregnable to mean ‘something that can not be taken.’

Since moving into the mansion, Connie has devised an impregnable burglar alarm system to make sure that no one can possibly take over her palatial estate.