- 揭老底 jiēlǎodǐ to expose secretsTo reveal the inside story or open a buried secret; to uncover someone's past or background.
- 老底儿 lǎodǐr the real storysomeone's background or past history; the inside story or the truth of a matter
- 老底子 lǎodǐzi background; pedigreeThe truth about someone's past, private affairs, or family history; one's background, secrets, or ancestry