2.AdjectiveOf the hand, forearm or foot: turned facing away from the body; with the thumb inward or big toe downward.
"The hand is in the prone position typically when using a keyboard; and the forearm is then also in the prone position; when the foot is resting on the inner side of the sole, it is in the prone position."
3.AdjectiveHaving a downward inclination or slope.
4.AdjectiveShooting from a position while lying down.
5.AdjectivePredisposed, liable, inclined.
"prone to failure"
6.VerbTo place in a prone position, to place face down.