To place in a prone position, to place face down.
"The nurse carefully placed the patient on his back before turning him over to put him in a prone position."
In plain English: To be prone means to lie flat on your stomach with your face pointing down.
"The cat was prone on the rug for hours before she finally decided to get up and stretch."
Usage: Do not use this verb form; the word prone is an adjective meaning likely or inclined to do something, while placing someone face down requires specific phrasing like "lay" or "place." Avoid confusing it with similar-sounding words by remembering that no standard English sentence uses "prone" as a transitive action.
Lying face downward.
"The injured hiker was found prone in the snow until rescue workers arrived."
The word prone comes from the Latin phrase meaning "bent forward" and traveled into English via Middle English to describe a position where someone is lying face down. Its original sense of being turned toward the front has remained consistent in its modern usage.