referee

Compared meaning: the official who enforces rules in a sports match (noun).

比较义项：体育比赛中负责执法、判罚的裁判（名词）。

• referee 本词

  The standard, full word for the official who enforces the rules; neutral register, natural in formal writing, official reports, or careful speech.

  这是标准、完整的说法，指负责执行规则的裁判；语域中性，适合正式书面语、官方报道或措辞严谨的场合。

  The football association appointed an experienced referee for the cup final.

  足球协会为杯赛决赛指派了一位经验丰富的裁判。

• ref

  An informal, shortened form of 'referee', common in casual spoken English, especially among fans or players reacting during a match.

  这是 referee 的非正式简称，常见于口语，尤其是球迷或球员在比赛中随口反应时使用。

  Hey, the ref made a terrible call in the last minute!

  喂，裁判在最后一分钟判得太离谱了！

Referee and ref refer to the same person, but differ in register: referee is the standard, complete word, common in formal contexts and writing; ref is an informal short form, used in casual talk or during a match.

referee 和 ref 指的是同一种人，但语域不同：referee 是标准、完整的说法，正式场合和书面语中常用；ref 是口语中的简略说法，多用于日常交谈或比赛现场的随口称呼，语气更随意。

Compared meaning: to judge a sports match or dispute (verb).

比较义项：担任裁判，裁定比赛或争端（动词）。

• referee 本词

  Used mainly for sports with a single official who can also actively intervene physically, such as football, boxing or rugby; the referee often blows a whistle and can stop play directly.

  主要用于由一名裁判执法、且该裁判有时需要亲自介入比赛的运动，如足球、拳击或橄榄球；裁判常吹哨并可直接叫停比赛。

  He has refereed top-flight football matches for over a decade.

  他已经执法顶级足球联赛的比赛超过十年了。

• umpire

  Used mainly for sports where officials watch from a fixed position and make calls without physically intervening, such as cricket, tennis or baseball.

  主要用于裁判从固定位置观察并做出判罚、而不亲自介入比赛的运动，如板球、网球或棒球。

  She umpired the tennis final and overruled a controversial line call.

  她担任那场网球决赛的裁判，并推翻了一个有争议的界内判罚。

Both mean to judge a match, but for different sports. Referee fits sports where officials can step in physically, like football, boxing, or rugby. Umpire fits sports where officials watch from a fixed spot, like cricket, tennis, or baseball. Its noun sense isn't compared.

这两个词都指在比赛中执法、维持规则，但适用的运动项目不同，不能随意互换；这里不比较 referee 作名词时指“裁判员”这一身份用法，只比较其动词用法。