A horse that has broken free of its reins is hard to control.
Tips
usage
缰 alone refers to the bridle/reins in general. The compound 缰绳 specifically means the reins (the rope). The idiom 脱缰之马 (a horse that has broken its reins) is used figuratively for something uncontrollable.
Silk radical on the left places 缰 in the rope-and-cord family, reins, lead, and halter are all made of woven leather or twisted cord. Same radical anchors 绳 rope, 线 line, 缚 bind, 绑 tie.
Right side supplies the sound: jiāng to jiāng (exact match). 畺 pictures field boundaries stacked between borders and faintly evokes the idea of containment, fitting for reins that hold a horse within bounds. Same phonetic anchors 疆 frontier and 僵 stiff.
