夜郎自大的英文：
[Literal Meaning]
the state of Ye Lang/self-conceited
ludicrous conceit of the king of Yelang

[解释]
人无知而狂妄自大。

[Explanation]
parochial arrogance

[例子]
你还和他吹嘘你有钱，别夜郎自大了。他可是我们这里有名的百万富翁。

[Example]
You've boasted you are rich to him. You are stuck up and he is the well-know millionaire here.

[英文等价词]
to get too big for one's shoes
be stuck up

• A cock is valiant on his own dunghill
  夜郎自大
• Every cock crows on its own dunghill
  夜郎自大
• Having limited outlook and being ignorantly boastful are common failings of the people in opposition to the reform.
  坐井观天，夜郎自大，是反对改革的人的通病。
• Keep it, in any case, familiar, facetious even, rather than pedantic and portentous
  无论如何，要使它显得很随便，甚至滑稽可笑，而不要显得很迂腐，夜郎自大。
• He was handsome and unattractive, a swashbuckling, beefy, conceited man who was putting on fat
  他样子挺英俊，可就是不讨人喜欢;长得结实粗壮，身子已经开始发胖，这个人夜郎自大，欺软怕硬。