prone - to be prone to (sth.)

Etym. online
c. 1400, "naturally inclined to something, apt, liable," from Latin pronus "bent forward, leaning forward, bent over," figuratively "inclined to, disposed," perhaps from adverbial form of pro- "before, for, instead of" (see pro-) + ending as in infernus, externus. Meaning "lying face-down" is first recorded 1570s.