/bʌf; bʌf/
n [U]
1 (a) strong soft dull-yellow leather 柔韧的暗黄色的皮革.
(b) colour of this 暗黄色.
2 (idm 习语) in the `buff (infml 口 esp Brit) with no clothes on 一丝不挂; 赤身露体. strip to the buff => strip.

adj made of or having the colour of buff 用柔韧的暗黄色皮革制的; 暗黄色的
*a buff envelope, uniform 牛皮纸信封、暗黄色制服.

v [Tn, Tn.p] ~ sth (up) polish sth with a soft material （用柔软的材料）擦亮、抛光某物
*buff (up) shoes with a cloth 用布把鞋擦亮.

/bʌf; bʌf/
n (preceded by a n 前接名词) (infml 口) person who is enthusiastic and knowledgeable about a specified subject or activity （某方面或某活动的）爱好者, 行家
*a film, an opera, a tennis buff 电影、歌剧、网球爱好者.