The kanji 胆 primarily represents the "gallbladder," the organ that stores bile. It can also figuratively refer to "courage," "nerve," or "guts," reflecting the perceived association between the gallbladder (or other internal organs) and one's emotional state or bravery.

・On-yomi (音読み): タン ・Kun-yomi (訓読み): きも

⚫︎ 胆力（たんりょく） Translation: Courage; grit; nerve. ⚫︎ 肝胆相照らす（かんたんあいてらす） Translation: To be frank with each other; to confide in each other; to be bosom friends (literally: to show one's liver and gallbladder to each other). ⚫︎ 小心（しょうしん） Translation: Cowardice; timidity; faintheartedness (literally: small 胆).

The kanji 胆 is a phono-semantic compound. It combines the radical 月 (にくづき), which originally represented "meat" or "flesh" and is related to the body, with 旦 (タン) , which originally referred to "dawn" or "daybreak". The inclusion of 月 (にくづき) provides the semantic component, indicating that the kanji is related to a part of the body. The 旦 element provides the phonetic component, suggesting the pronunciation "tan." The whole kanji originally depicted the gallbladder itself and was later extended to include the metaphorical sense of "courage" and "nerve."