be all hat and no cattle

(US informal)tend to talk boastfully without acting on one's words

(美，非正式)空谈，夸夸其谈

black hat (或 white hat)

used in reference to the bad (or good) party in a situation (from the colour of hat traditionally worn by the bad (or good) character in Western films)

［用于指西部片场景中可通过帽子颜色判断出来的坏人或好人］黑帽（或白帽）

we are the good guys—the black hats lost.

我们是那些好人——黑帽子坏人输了。

hats off to ——

used to express admiration for someone who has achieved something or done something praiseworthy

向…致敬

hats off to them for agreeing to work for the day to raise money.

向同意在筹款日参加工作的人们致敬。

keep something under one's hat

keep something a secret

将…保密

pass the hat round (或北美pass the hat)

collect contributions of money from a number of people for a specific purpose

筹集钱款

pick something out of a hat

select something, especially the winner of a contest, at random

随机挑出（尤指比赛中的获胜者）

take one's hat off to

used to state one's admiration for (someone who has achieved something)

向 （取得成就之人）…致敬（或表示钦佩）

throw one's hat in or into the ring

express willingness to take up a challenge

欣然迎战，接受挑战

at the drop of a hat

At the slightest pretext or provocation.

以很小的事为借口或因很小的事而激怒

hat in hand

In a humble manner; humbly.

卑躬屈膝地；谦恭的

pass the hat

To take up a collection of money.

募捐：进行钱的募集

take (one's) hat off to

To respect, admire, or congratulate.

向某人表示赞赏、钦佩或祝贺

talk through (one's) hat

To talk nonsense.

胡说八道

To bluff.

虚张声势

throw (one's) hat into the ring 或 toss (one's) hat into the ring

To enter a political race as a candidate for office.

参加竞选：作为职位的候选人参加政治竞赛