Qual a diferença entre pants e trousers? Confusing words: pants, trousers and slacks

Pants: Pants are clothing for the body. However, it has two distinct meanings which vary between regions.

American English: Trousers 

Pants in American English (Blue jeans)

In American English , pants are a long outer garment worn at the hips, which in British English are called trousers.

"Trousers" can either be synonymous with "pants" or have a more formal connotation. Therefore, all trousers are pants, but not vice-versa; jeans are pants but not trousers, while slacks (formal pants) are both. This definition is consistent with other languages such as the Spanish pantalones, which is contrasted with pantalones cortos (shorts, or literally "short pants"). This usage is also common in parts of the North West of England.

Other uses in American English:

Pants is a crucial part of many popular slang phrases, such as "I'm gonna blow your pants off." This phrase suggests extreme surprise and excitement caused by another's actions. The term was first coined during a local radio show recorded in Greenhills, Ohio. Example of use: "Did you really just flex your abs and rip through your shirt? You just blew my pants off."

To "pants" someone (used interchangeably with "de-pants") colloquially means to pull a victim's pants down in public.

British English: Underpants

Pants in British English (Women's knickers)

In British English, pants are undergarments known variously as underwear or underpants.

It is a catch-all term that can denote anything from g-strings to boxer shorts, but all have the common feature that they are worn under trousers, skirts or pyjamas. In Japan, the word pantsu (パンツ) is a loanword from the English word "pants" and means underpants.