1. To lie flat, especially on one's front. The soldiers proned out as soon as they heard the gunshots. I proned out for a while under the shade of a large sycamore tree, listening to the babble of the brook beside me.
2. To cause someone to lie flat, typically on their front. In this usage, a noun or pronoun can be used between "prone" and "out." The police officers proned out the suspect and searched him for weapons. The old drunkard had been proned out by whiskey and beer.
3. Of a surfer, to lie flat on one's board in front of a wave, especially as a means of getting back to shore. The water was becoming too crowded with tourists and novices, so I just proned out and rocketed toward the shore.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.