1 (a) brother of one's father or mother; husband of one's aunt 伯父; 叔父; 舅父; 姑父; 姨父
*my uncle Jim 我的吉姆叔叔. =>App
(b) man whose brother or sister has a child 当叔父、伯父、舅父、姑父或姨父的人
*Now you're an uncle. 现在你当上叔叔了.
2 (infml 口) (used by children, esp in front of a first name 用作儿语, 尤用于名前) unrelated adult male friend, esp of one's parents 无亲戚关系的成年男姓朋友（尤指父母的朋友）; 叔叔; 伯伯.
3 (idm 习语) bob's your uncle => bob4. talk like a Dutch uncle => talk2.
1200-1300; Language: Old French;Origin:Latin
avunculus 'mother's brother'
the brother of your mother or father, or the husband of your aunt
→aunt I went to stay with my uncle and aunt for a few days. Uncle Philip I was very excited about becoming an uncle (=your sister or your brother's wife has a child) .
used by children, in front of a first name, to address or refer to a man who is a close friend of their parentssay uncleAmE spoken
used by children to tell someone to admit they have been defeated
1. Tom mimicked his uncle´s voice and gestures perfectly. 汤姆把他叔叔的声音和姿态模仿得惟妙惟肖.
2. The most enduring portrait of Uncle Sam was created by artist James Montgomery Flagg in his famous army recruiting posters of World Wars I and II. 最令人难忘的山姆大叔的画像，是由画家詹姆斯·蒙哥马利·弗拉格创作的，他在两次世界大战期间画了很多著名的征兵招贴画。
3. He refused to live in dependence on his uncle. 他拒绝依靠他叔叔生活。
4. He disclaimed a share in his uncle´s estate. 他放弃对他叔叔财产的继承。
5. Don´t ever say that again. My uncle is very conscious. 千万别再那么说,我叔叔非常敏感.
6. After an exile of ten years her uncle returned to Britain. 她叔叔背井离乡十年後返回英国.
7. An uncle is a relation. 叔叔（舅舅）是亲属。
8. And maybe they affected a neighborhood business or a friend's uncle. 也许它们还影响到了附近的一家商店或一位朋友的叔叔。
9. According to one story, when a government official visited the plant and asked about the letters, a creative employee told him "US" was short for "Uncle Sam" Wilson. 传说有一回，有个政府官员来参观加工厂，问及这些字母的含义，一个想像丰富的雇员告诉他，"US"是"山姆大叔"威尔逊的缩写。
10. After the war, a character called Uncle Sam began appearing in political cartoons, his form evolving from an earlier cartoon character called Brother Jonathan that was popular during the American Revolution. 战后，政治漫画里开始出现了一个名叫"山姆大叔"的人物。他的原型是一个早期漫画人物，名叫乔纳森大哥，此人在美国独立战争时期非常出名。