infirmity

As nouns the difference between infirmity and infection

is that infirmity is feebleness, frailty or ailment, especially due to old age while infection is (pathology) the act or process of infecting.

As nouns the difference between infirmity and melancholy

is that infirmity is feebleness, frailty or ailment, especially due to old age while melancholy is (historical) black bile, formerly thought to be one of the four "cardinal humours" of animal bodies.

As an adjective melancholy is

affected with great sadness or depression.

As nouns the difference between infirmity and informity

is that infirmity is feebleness, frailty or ailment, especially due to old age while informity is (obsolete) absence of regular form; shapelessness.

As nouns the difference between taxonomy and infirmity

is that taxonomy is the science or the technique used to make a classification while infirmity is feebleness, frailty or ailment, especially due to old age.

As nouns the difference between infirmity and health

is that infirmity is feebleness, frailty or ailment, especially due to old age while health is the state of being free from physical or psychological disease, illness, or malfunction; wellness.

As nouns the difference between infirmity and disposition

is that infirmity is feebleness, frailty or ailment, especially due to old age while disposition is disposal.

As nouns the difference between infirmity and affliction

is that infirmity is feebleness, frailty or ailment, especially due to old age while affliction is a state of pain, suffering, distress or agony.