‘弹丸’ (dàn wán) literally combines ‘弹’ (dàn), meaning ‘projectile’ or ‘bullet’, and ‘丸’ (wán), meaning ‘ball’ or ‘pellet’. Together, it refers to a small, spherical projectile — historically a cannonball made of iron or stone, and today commonly a metal pellet used in air guns or hunting. Though its original military sense remains in historical or literary contexts, modern usage often appears in idioms like ‘弹丸之地’ (a tiny territory), emphasizing extreme smallness.

The term carries a vivid, slightly archaic or literary tone and is rarely used for everyday bullets (which are usually ‘子弹’ zǐdàn). It’s also used metaphorically to describe anything compact yet potent — for instance, a small but influential country may be called a ‘弹丸小国’. In zoology, it occasionally appears in compound terms describing round, pellet-like animal excretions (e.g., owl pellets: 鸟类弹丸), linking it to the ‘Animals’ topic via biological context.