See prone in Webster's New World Roget's A-Z Thesaurus II
adjective
Lying down:
decumbent, flat, horizontal, procumbent, prostrate, recumbent. See horizontalHaving or showing a tendency or likelihood:
apt, disposed, given, inclined, liable, likely. See likelyTending to incur:
liable, open, subject, susceptible, susceptive, vulnerable. See likely
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