パイセン

noun

senior; upperclassman; older colleague

Slang reversal of 先輩 (せんぱい). Used playfully or casually among friends, often by younger people. Can sound cheeky or affectionate depending on context.

See also: 先輩 (せんぱい)

• パイセン、今日きょうもお疲つかれっす！

  Hey senior, thanks for your hard work today!

• あのパイセン、めっちゃ面おも白しろいんだよね。

  That upperclassman is really funny.