What is a short word for gentlemen?

There isn't a single perfect one-word replacement for "gentlemen" that captures all its nuances. Here are some options depending on the context:

Formal:

* Gents: A more casual and friendly version of "gentlemen".

* Sirs: Used when addressing a group of men respectfully.

Informal:

* Guys: A common and casual term for a group of men.

* Fellows: More informal than "gentlemen", often used in a friendly way.

* Blokes: A British informal term for men.

The best choice depends on the specific situation and desired tone.