noun
Refers to a bullet that misses its intended target and hits something else. Used in literal firearm contexts and metaphorically for unintended consequences.
銃撃戦でそれ弾に当たった。
I was hit by a stray bullet in the shootout.
彼の批判はそれ弾のように私にも向けられた。
His criticism was directed at me like a stray bullet.
流れ弾 also means stray bullet, but emphasizes a bullet that has gone astray in the course of shooting, often in a chaotic situation. それ弾 focuses more on the bullet missing its target.
Compound of それ (stray, from verb 逸れる) and 弾 (bullet). The kanji 逸れ explicitly means 'stray' or 'deviate'.