means A steep cliff edge or the very brink of a dangerous drop — literally or, more often, figuratively as the verge of disaster.

from From Latin 'praecipitium,' a headlong fall, built from 'praeceps' meaning 'headfirst' — itself 'prae-' (before) plus 'caput' (head). So a precipice is, at root, the place where you go head-over-heels, the etymology already tumbling you forward before you've decided to step.