That which begins or originates something; the source or first cause.
The act of doing that which begins anything; commencement of an action, state, or space of time; entrance into being or upon a course; the first act, effort, or state of a succession of acts or states.
The initial portion of some extended thing.
That which is begun; a rudiment or element.
Of or relating to the first portion of some extended thing.
The point at which something begins.
Originally, the point on the land or water surface below which a nuclear bomb detonates in the air; now also the point on such a surface at or above the detonation.
The location of any disaster or violent assault.