A major event in one's life, normally bringing about a substantial change.

(probability theory) An event that contains no possible outcomes and thus cannot possibly occur; an empty set.

(probability theory) An event that contains all of the possible outcomes and thus is known a priori to be certain to occur; the entire sample space.

Alternative form of in any event

(chemistry) A period of time when large expanses ocean are depleted of dissolved oxygen.

(astrophysics) The gravitational sphere of a black hole within which the escape velocity is greater than the speed of light. / (by extension) A point of no return.

plural of event horizon

(medicine) Any unanticipated or unusual event in a medical setting which results in death or serious physical injury to a person or persons, specifically including limb loss or gross motor function.

A public event such as a ballgame, parade, or festival that requires transportation planning, especially including roadway closure, and often a city permit in consequence.

The formation of a cloud of calcium carbonate precipitate in a body of water during the summer, as a result of change in water temperature or increased photosynthetic activity by certain microscopic marine organisms.