prophet of doom 悲观论者；悲观预言家

【例句】
The prophets of doom who said television would kill off the book were wrong.
认为电视会扼杀书籍的悲观预言家完全错了。

Bill is sure that our new business will fail-he's such a prophet of doom!
比尔断定我们的新企业一定会失败－他真是一个悲观论者。