Noun

1. A crack or fissure in a glacier or snow field; a chasm.
2. A discontinuity or “gap” between the accounted variables and an observed outcome.
   • 1954: Gilbert Ryle, Dilemmas: The Tarner Lectures, 1953, dilemma vii: Perception, page 105 (The Syndics of the Cambridge University Press)

     [… H]e laments that he can find no physiological phenomenon answering to his subject’s winning a race, or losing it. Between his terminal output of energy and his victory or defeat there is a mysterious crevasse. Physiology is baffled.

Verb

1. first-person singular imperfect subjunctive form of crever