坦白 literally combines 坦 (tǎn, 'open, level, unobstructed') and 白 (bái, 'plain, clear, pure'), together conveying the idea of speaking plainly and openly without concealment. As an adjective, it describes a person’s honest, forthright character or tone — e.g., a 坦白的态度 ('frank attitude'). As a verb, it means 'to confess' or 'to admit candidly', often used in contexts involving wrongdoing, vulnerability, or emotional disclosure.

This word carries a slightly formal or serious tone and is commonly found in interpersonal communication, psychological discussions, legal settings (e.g., confessing to authorities), or self-reflection. It implies moral courage — not just stating facts, but doing so with sincerity and willingness to face consequences. Unlike casual honesty (e.g., 真实), 坦白 suggests intentional openness, sometimes after hesitation or pressure.