The characters literally combine to mean “Forgive my direct speech.” The structure is brilliant for its social function: it asks for forgiveness *before* the potentially offensive statement is even made, which significantly softens the impact of the directness to come.
恕我直言 (shù wǒ zhí yán) is a perfect window into the Chinese cultural concepts of “face” (面子, miànzi) and social harmony. In a culture that often prefers indirect communication to avoid confrontation, this phrase serves as a crucial, socially-sanctioned tool for when directness is necessary. Compared to the English “With all due respect,” 恕我直言 carries a slightly different weight. In Western cultures, “With all due respect…” or “No offense, but…” can sometimes be used passive-aggressively or sarcastically, as a prelude to an attack. While this is possible with the Chinese phrase, it is far less common. 恕我直言 is more often perceived as a genuine attempt to show respect for the listener's feelings and social standing (giving them face) while fulfilling a duty to be honest. It's an acknowledgement that “I know this is not the preferred way to communicate, but the situation calls for it, and I still respect you.” It masterfully balances the conflicting needs for directness and politeness.
This phrase is versatile and appears in both formal and serious personal situations.
The tone is almost always serious and formal. It's not a casual phrase to be thrown around lightly.