county in Hebei province
鄗 is a rare kanji used primarily as a place name, specifically a county in Hebei province. Its standalone meaning is tied to that geographical reference.
鄗 combines 高 (tall, high) with the city enclosure ⻏, likely representing a place name. The exact historical development is uncertain.
The left side 高 suggests something high or elevated, and the right side ⻏ is a city wall. Picture a high-walled county in Hebei province.
For コウ, imagine a high (高) county whose name sounds like コウ. The tall walls of the county echo the reading コウ.