Definition of "Weakness" :

noun: the property of lacking physical or mental strength; liability to failure under pressure or stress or strain

"His weakness increased as he became older."

noun: powerlessness revealed by an inability to act

"In spite of their weakness the group remains active."

noun: a penchant for something even though it might not be good for you

"He has a weakness for chocolate."

noun: a flaw or weak point

noun: the condition of being financially weak

"The weakness of the dollar against the yen."