a dead duck
1. A person or thing that is useless or hopeless. That new budget bill was a dead duck before it hit the Senate. That mechanic turned out to be a dead duck. He didn't even know how to change my oil.
2. Someone who is about to be in a great deal of trouble for something they have done. When Mom finds out you snuck out of the house to meet your boyfriend, you're going to be a dead duck!
a dead duck
1. If someone or something is a dead duck, they are a failure. The government is a dead duck; and the Supreme National Council does not have the means to govern. The movie's probably a dead duck.
2. Someone who is a dead duck is going to be punished severely. Hit me on the head again, and you're a dead duck.
a dead ˈduck(informal) a plan, an idea, etc. that has failed or is certain to fail and that is therefore not worth discussing: The new supermarket is going to be a dead duck; there’s no demand for one in this area.
dead duck, a
A has-been or a loser. The term dates from the second half of the nineteenth century and may have been derived from lame duck. At first it denoted a person whose political influence had declined. Later it simply came to mean someone who has no hope of winning, or who has already lost.
See also: dead