That which prevents success, or renders it difficult; a state not favorable to successful operation. The army commenced an attack on the enemy, notwithstanding the disadvantage of its position.

Any unfavorable state; a state in which some loss or injury may be sustained. Hence,

Loss; injury; prejudice to interest, fame, credit, profit, or other good; as, to sell goods to disadvantage.

To injure in interest; to prejudice.