In Jainism, Purva (singular: Purva) means “ancient” or “earlier.” It is used for the very old Jain scriptures or treatises that are considered part of the early, now largely lost, canonical literature.

• Purvas: These are the earliest Jain scriptures believed to have been taught by Tirthankaras before the later canonical Angas. They covered philosophy, ethics, cosmology, and code of conduct.
• Loss and status: Most traditions hold that the Purvas were vast and were lost over time. What remains are later texts that reference or summarize their ideas.
• Number: Different traditions give different numbers for the Purvas, but a common belief is that there were 14 Purvas in the early tradition. Some accounts vary depending on Digambar vs. Shwetambar sources.

In short, 1 Purva would be one of these ancient, now mostly inaccessible treatises that form part of the foundational but largely lost layer of Jain scriptural knowledge.