"deprive of necessary disqualifications," 1718 (implied in disqualified), from dis- + qualify. Related: Disqualifying.

1710s, "that which disqualifies;" 1770, "act of disqualifying; state of being disqualified;" noun of action or state from disqualify.

1640s, "render obsolete," back-formation from superannuated. Meaning "impair or disqualify by old age" is from 1690s. Related: Superannuating.

1550s, "not having necessary qualifications, from un- (1) "not" + past participle of qualify (v.). Meaning "not modified or limited" is recorded from 1796. As a verb, unqualify "disqualify" is from 1650s.