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.
source and origin