Formal:
* Commencement: This word implies a formal start.
* Initiation: This word suggests a process of starting something.
* Inception: This word emphasizes the original point in time when something began.
* Onset: This word emphasizes the beginning of a process or event.
Informal:
* Start: This is the most straightforward synonym.
* Launch: This word suggests a dramatic or energetic beginning.
* Kick-off: This word implies the start of something exciting.
* First: This word indicates the initial stage or position.
Literary:
* Genesis: This word refers to the origin or creation of something.
* Dawn: This word implies the start of a new era or period.
* Outset: This word emphasizes the very beginning of something.
The best word to use will depend on the specific situation and the desired tone.