Impregnable is an adjective that is used to describe something which is unconquerable. Able to resist or withstand an attack. Not to be overcome or overthrown. Not likely to be weakened or changed.
- He is an ‘impregnable’ individual who can withstand anything that life throws at him.
- They built an ‘impregnable’ castle which is so strong, high and wide that no person in the right mind would even think about attacking them.
- Their love is ‘impregnable’, no other can break or influence what they have.