A buff usually means a person who is very interested in a subject and knows a lot about it —for example, a movie buff or history buff. It can also mean muscular/fit in informal slang, or refer to a pale yellow- brown color in other contexts.

Common meanings

  • Enthusiast: someone deeply into a topic, like a car buff or music buff.
  • Fit/muscular: informal slang, as in “He’s really buff.”
  • Color/material sense: a light yellow-brown color, or something made of buff leather.

Quick examples

  • “She’s a film buff.”
  • “He looks buff after months at the gym.”
  • “The folder was made from buff-colored paper.”

In plain English

If someone calls you a buff , they usually mean you’re a fan who knows a lot about something. If they say someone is buff , they usually mean the person is very fit.

TL;DR: “Buff” most commonly means an enthusiast , but it can also mean muscular or yellow-brown.