One way to hold this word: a strong beam thrown forward from the front of a vehicle, cutting a bright path through the dark. The lamp sits at the very front, the light travels ahead of the car, and anything standing in that beam is suddenly lit up and completely visible.
Wiktionary records the word as a compound of head + light: the lamp on the front (the 'head') of a vehicle.
Wiktionary 記的來源是 head + light 的組合：裝在車子「頭」上的燈。這條線索直接對上畫面裡的位置——在最前面，朝前打光。
Wiktionary (kaikki extract), headlight, etymology: "From head + light."
From the picture
被那道光照住的一瞬間
把畫面裡的位置換一下：不是坐在車上往前看，而是站在光裡被照。
noun · B2
Used to describe someone who is so frightened, shocked or confused that they freeze and do nothing, the way an animal standing in a car's headlights stops still instead of moving out of the way.
嚇得愣住
noun · B1
One of the large lamps at the front of a car, bus, train or other vehicle, or the strong beam of light that such a lamp throws out ahead of it.
車頭燈