Impregnable
Part of speech: adjective
Definition: (Of a fortress, wall, etc.) Too strong to be penetrated.
Strong
Part of speech: adverb
Definition: in a strong manner
Part of speech: adjective
Definition: capable of producing great physical force.capable of withstanding great physical forcefast moving water, wind, etc, which has a lot of power.determined, unyieldinghighly stimulating to the senseshaving an offensive or intense odor or flavorhaving a high concentration of an essential or active ingredienthaving a high alcoholic contentinflecting in a different manner than the one called weak, such as Germanic verbs which change vowelsnot easily subdued or takenimpressive, good
Example sentence: Fire is the test of gold; adversity, of strong men.