Definition of "one-seed" [one-seed]

• Having a single seed (adjective)

WordNet. Princeton University. 2010.

• "In fact, the one-seed Capitals lost to the eight-seed Montreal Canadiens last season, in a 4-3 series."
• "To make it, Butler had to beat an updated version of itself on Saturday: Virginia Commonwealth University, a wildly entertaining 11th seed that had charged into the Final Four by stunning one-seed Kansas, busting President Obama's tournament bracket and even making the NCAA feel good about its goofy "First Four" gimmick VCU was a First Four appetizer that somehow survived until the dessert course."
• "For second-seeded Pittsburgh, it is hard to imagine losing a one-seed, regardless of how they play."