Definitions for "disqualify"
To deprive of the qualities or properties necessary for any purpose; to render unfit; to incapacitate; -- with for or from before the purpose, state, or act.
To deprive of some power, right, or privilege, by positive restriction; to disable; to debar legally; as, a conviction of perjury disqualifies a man to be a witness.
make unfit or unsuitable; "Your income disqualifies you"
To officially move a rider to last as a result of any rule infraction.
When the stewards lower a horse's actual finishing position if the horse interfered with others during the race, carried improper weight, or was drugged.
To officially lower a horse's actual finish position due to interfering with other horses, carrying too little weight, not conforming to conditions of eligibility of having systemic substances above allowed limits.
Keywords:  ineligible, event, play
To make ineligible for further play in an event.