Ancient people often used oaths and curses to bind enemies.
Tips
usage
诅 mostly appears in the compound 诅咒 (zǔzhòu, to curse). On its own it is rare and feels classical — you'll meet it in idioms or historical texts more than daily speech.
memory
言 (speech) + 且 — words spat out 'and yet again' until they harden into a curse.