One way to hold this word: the straps over a horse's head, with a metal bit in its mouth and two reins running back to your hands. The point of the picture is not tying up — the horse can still walk, turn, and run. The point is that you are connected to it, so a small pull travels straight through and the animal slows, turns, or waits. Hold that line in your mind and most of the other uses of bridle come into view.
From the word’s history
From Middle English bridel, from Old English brīdel, from Proto-West Germanic *brigdil and Proto-Germanic *brigdilaz, meaning strap or rein; the source analyses it as braid plus -le, so the underlying idea is a plaited strap.
來自中古英文 bridel、古英文 brīdel，再往前是原始日耳曼語 *brigdilaz，意思是「帶子、韁」。來源把它分析成 braid（編）加上字尾 -le，也就是「編起來的帶子」。這條線索跟今天的核心畫面剛好對得上：它到現在都還是一組繞在馬頭上的皮帶。
Wiktionary, English entry 'bridle' (packet source_ref kaikki:3f6f69a190036ae4:858274251)
登入就可以看每一支怎麼連回核心畫面。