According to definition, the name "Celtic" is a branch of the Indo-European family of languages—including Irish, Scots' Gaelic, Welsh, and Breton—which survive now in Ireland, the Scottish Highlands, Wales, and Brittany.
But, the Celtics in Boston are team of basketball players assembled from other teams—Kevin Garnett from the Minnesota Timberwolves, Ray Allen, the Seattle SuperSonics, James Posey, the Miami Heat, and Glen Davis, Louisiana State University—who did more than survive this season unlike last year.
After a dismal performance last season (second worse record in the NBA: 24-58), fans were expecting them to win—or make the playoffs at least.
After a blockbuster trade (which included trading six players to Minnesota!) to acquire Kevin Garnett, the Celtics totally revamped their team.
They also acquired Ray Allen from the SuperSonics in order to create a trio of scoring threats which started the whispers that they were now the team to beat in the NBA.
The only true weaknesses I saw with this team were their point guard and center positions.
Rajon Rondo (averaged 3.8 assist last season) stepped up to be a floor general and led the talented trio. He ultimately determined the fate of the team in every game.
The weak link was Kendrick Perkins (6’10”), who has yet to display the ability to either rebound (4.6 rebounds per game over four years as a pro) decently, or score proficiently (4.0 point per game averaged in four years as a pro).
All in all, the Boston Celtics worked together as a cohesive unit, and now have a shot at an NBA title.
All that remains to be seen is whether they can finish a team in under seven games.