自愧不如 is a four-character idiom meaning 'to feel ashamed of one's own inferiority'—a deep, self-reflective sense of inadequacy when comparing oneself to someone else’s admirable qualities, skills, or achievements. Literally, it breaks down as 自 (self), 愧 (ashamed/guilty), 不 (not), and 如 (to equal/be like). Together, it expresses the feeling that 'I am not even worthy of comparison' — not just recognizing a gap, but experiencing humility or embarrassment about it.

This phrase is formal and literary, often used in writing or elevated speech. It commonly appears alongside 羡慕 (to admire/envy), forming the pair 自愧不如＋羡慕: acknowledging both admiration for another and discomfort at one’s own shortcomings. It implies sincerity and introspection—not jealousy or resentment, but respectful self-awareness. While it can stand alone, it frequently follows a clause describing what triggers the feeling (e.g., after seeing someone’s talent or integrity).