Aarambh (often spelled aarambha) means the beginning or commencement of something. It is a general Sanskrit/Hindi word used for the start of an action, project, ritual, or practice.

In Jain usage, there isn’t a special technical doctrine attached to the word beyond its ordinary sense of “beginning” or “start” of a practice, vow, or activity. If you’d like a Jain reference or usage in a particular text, I can look into that specific context.