诤友

諍友
zhèngyǒu
a friend capable of direct admonition

CEDICT

  1. (literary) friend who will give unreserved criticism
  2. friend who will give unreserved criticism

Wiktionary

能直言规劝的朋友

維基詞典

Entry Composition

1 诤 zhèng
  1. to admonish
  2. to warn sb of their errors
  3. to criticize frankly
  4. Taiwan pr. zhēng
2 友 yǒu friend