请看外电相关报道：Federline appeared in the movie "You Got Served" and performed as a backup dancer for singer Justin Timberlake, Spears' former boyfriend(前男友). He was previously involved with actress Shar Jackson of TV's "Moesha." Federline and Jackson have two children.
在这段话中，词组“backup dancer”值得一提，汉语中的“伴舞演员”就可用它来表达。“Backup”在这里指为主唱“伴奏”、“伴唱”或“伴舞”，如：backup band（伴奏乐队）；band singer（伴唱歌手）。
另外，我们常说的“备份”也可用“backup”来形容，如：backup file（备份文件）；backup diskette（备份软盘）。
