One way to hold this word: American baseball is stacked in layers, and the Major Leagues are the top layer, with the minor leagues underneath. To call something major-league is to point at that top layer. Everything the word does grows out of that one picture — first about actual baseball, then about any field where some people and some problems sit at the top and the rest sit below.
One branch
最上面那一層
兩個意思共用同一張分層圖，差別只在這張圖套在什麼上面：一個套在棒球，一個套在其他任何領域。
adjective · B2
Belonging to the Major Leagues, the top level of professional baseball in the United States. It is used in front of a noun, about the players, teams, games and stadiums at that level.
大聯盟的