backlog
n (usu sing 通常作单数) accumulation of work or business not yet attended to 积压的工作; 待办的业务
a backlog of work, unanswered letters 积压的工作[待覆信件]
After the postal strike there was a huge backlog of undelivered mail. 邮政部门罢工以後, 大量邮件积压下来.
Of course he is. He's very successful. He's made lots of records. They broadcast a programme of his music last month on the radio. Why don't you come on Saturday? I think you'd enjoy it.