beginning — The beginning of an event or process is the first part of it.
cause — a person or thing that acts, happens, or exists in such a way that some specific thing happens as a result; the producer of an effect: You have been the cause of much anxiety. What was the cause of the accident?
commencement — The commencement of something is its beginning.
origin — something from which anything arises or is derived; source; fountainhead: to follow a stream to its origin.
plan — a scheme or method of acting, doing, proceeding, making, etc., developed in advance: battle plans.
source — any thing or place from which something comes, arises, or is obtained; origin: Which foods are sources of calcium?
start — to begin or set out, as on a journey or activity.
unlikelihood — the state of being unlikely; improbability.
improbability — the quality or condition of being improbable; unlikelihood.
