A person or team that takes part in a quarterfinal(noun)
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Use "quarterfinalist" in a sentence
"KJA said that finalist meant "top ten"; I wonder what "quarterfinalist" means..."
"- A baby was bawling, and Sony Ericsson Open quarterfinalist David Ferrer wasn't too happy, either."
"Open quarterfinalist Melanie Oudin 7-5, 6-2 to give the experienced Italians an insurmountable 3-0 lead over a young United States team in the best-of-five series on an outdoor clay court at the Rocco Polimeni club."