speaking engagement
noun [ C ] formal uk/ˈspiː.kɪŋ ɪnˌɡeɪdʒ.mənt/ us/ˈspiː.kɪŋ ɪnˌɡeɪdʒ.mənt/
（获邀就某事正式演说的）受邀演讲
an occasion when you have been asked to give a formal talk about something
He knows a lot about the history of this area, so he has many speaking engagements with local community groups. 他非常了解这个地区的历史，因此常常受邀在当地社区作报告。