What is theta also called?

Could you please elaborate on the term "theta" and inform me if it has any alternative names or monikers within the realm of cryptocurrency and finance? I'm particularly interested in understanding if theta is commonly referred to by another term in the industry, and if so, what that might be. Additionally, I'd appreciate it if you could provide a brief explanation of theta's significance and role within the cryptocurrency ecosystem. Thank you for your assistance in clarifying this matter.