A terminal device, a base station device, a communication system, a measurement method, and an integrated circuit, which are capable of efficiently performing Sidelink Direct Discovery, are provided. The terminal device, in a case where there exists at least one applicable neighboring cell to be reported to a measurement identifier with a measurement reporting procedure being triggered, a best neighboring cell up to a maximum cell number is included in a neighboring cell measurement result; and in a case where a measurement purpose of an associated reporting configuration is configured to report on monitoring of a Sidelink Direct Discovery announcement, CGI information about a cell indicated by a first parameter is obtained in an associated measurement object, and the cell broadcasts configuration information about the monitoring of the Sidelink Direct Discovery announcement, the configuration information about the monitoring of the Sidelink Direct Discovery announcement that has been acquired is included in measurement reporting.