喝

hè is a bound reading — 喝 does not stand alone as a modern verb. It only appears inside a small set of compounds: 喝彩 (to cheer / acclaim), 喝道 (to shout — usually introducing dialogue, like English 'barked'), 大喝一声 (to let out a roar), 当头棒喝 (a Chan-Buddhist wake-up shout), 开锣喝道 (to bang gongs and shout one's arrival). For everyday 'to shout' as a free verb, use 喊 instead.

当头棒喝 ('a blow on the head and a shout') comes from Chan/Zen Buddhism — masters in the Linji line would suddenly hit students with a stick or roar at them to jolt them out of conceptual thinking into direct awakening. The phrase now means any sharp wake-up call that snaps someone out of complacency.