Someone who physically resembles (looks like) someone else.(noun)
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Use "lookalike" in a sentence
"Maybe the DiCaprio lookalike is going to run around inside different paintings like in the 2nd Looney Tunes movie, chased by half the guys from MADTv."
"The Exile has the details and the download of part of the porn film, "Who's nailing Palin?" starring not only the Sarah Palin lookalike Lisa Ann but also a Hillary Clinton lookalike."
"Conan O'Brien coming face to face with his so - called lookalike, Finland's president."