noun
candid advice; frank advice; honest opinion
Often implies advice that is hard to hear but well-intentioned; commonly used in the phrase 苦言を呈する (to offer frank advice).
上司は私に苦言を呈した。
My boss gave me some frank advice.
彼は友人の行動について苦言を述べた。
He offered a candid opinion about his friend's behavior.