Fail-secure is a term used in electronic security systems to describe the state of a device or mechanism when power is lost or a system fails. There are several synonyms for fail-secure, including "locked secure," "fail-safe," and "safe mode." These terms are used to describe systems or mechanisms that are designed to prioritize safety and security in the event of a loss of power or system failure. Fail-secure systems are typically used in access control systems, locking mechanisms, and security doors. The use of fail-secure mechanisms ensures that security is maintained even in the event of a power outage or system failure, reducing the risk of unauthorized access and maintaining the safety of the occupants.