They decided to re-release the album with three previously unreleased tracks.

re-release 是由前缀 re-（表示"再次"）和动词 release（发行）组成的复合动词，字面意思是"再次发行"。 release 的意思是"发布、发行"，指将音乐、电影等作品公开发布给大众。 re-release 特指对已经发行过的作品进行再次发行，通常会加入新内容或进行重新制作。