• (RP) IPA: /pɹəʊn/
• (America) IPA: /pɹoʊn/

prone

1. Lying face downward.

   Synonyms: prostrate

   Antonyms: supine

   prone position

   • 1907, Robert William Chambers, chapter I, in The Younger Set, New York, N.Y.: D. Appleton & Company, OCLC 24962326 ↗:

     But they had already discovered that he could be bullied, and they had it their own way; and presently Selwyn lay prone upon the nursery floor, impersonating a ladrone while pleasant shivers chased themselves over Drina, whom he was stalking.

2. Having a downward inclination or slope.
3. Shooting from a lying down position.
4. (figuratively) Predisposed, liable, inclined.

   prone to failure

   • 1609, William Shakespeare, “Sonnet 141”, in Shake-speares Sonnets. Neuer before Imprinted‎^{[S%3Aen%3AShakespeare%27s_Sonnets_%281883%29%2FSonnet_141]}, London: By G[eorge] Eld for T[homas] T[horpe] and are to be sold by William Aspley, OCLC 216596634 ↗:

     Nor are mine ears with thy tongue's tune delighted; / Nor tender feeling, to base touches prone, / Nor taste, nor smell, desire to be invited / To any sensual feast with thee alone: {{...}

• neveling
• nuel

• French: couché sur le ventre
• German: in Bauchlage
• Italian: prono, prostrato, inchinato, reclino
• Russian: лежа́щий ничко́м
• Spanish: postrado, de bruces, decúbito prono

• French: enclin
• German: schräg
• Italian: pendente, inclinato, reclino, obliquo
• Portuguese: inclinado, prono
• Russian: накло́нный

• Russian: лёжа

• French: prédisposé, enclin
• German: anfällig, geneigt
• Italian: incline, predisposto, portato, disposto, orientato
• Portuguese: propenso
• Russian: скло́нный
• Spanish: propenso