The idiom "dead ringer" means that someone or something looks exactly like another person or thing. It is often used to describe a person who looks very similar to someone else, or an object that is identical to another.
For example, if you see two people who look almost identical, you could say that one of them is a "dead ringer" for the other. Or if you see a car that looks exactly like your friend's car, you could say that it's a "dead ringer" for your friend's car.
The origin of the phrase is unclear, but it may have come from horse racing. A "ringer" was a horse that was substituted for another horse in a race, and a "dead ringer" was a horse that was so similar to the original horse that no one could tell the difference.
In everyday conversation, "dead ringer" is a casual and informal expression that is often used to describe a strong resemblance between two things or people.
• The painting was a dead ringer for the original masterpiece.
• The imposter was a dead ringer for the CEO, fooling everyone in the boardroom meeting.
• The actor was a dead ringer for the real-life character he portrayed.
• She looks like a dead ringer for her mother.
• The counterfeit money was a dead ringer for the real currency.
• The new employee is a dead ringer for the previous one.