This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
鍕 combines the metal radical 金 with the phonetic component 軍, suggesting a metal object whose exact historical meaning is uncertain.
The left side is metal 金 and the right side is army 軍. Picture an unknown metal tool used by an ancient army, but its exact purpose is lost to time.
For クン, imagine a military commander named Kuhn inspecting a mysterious metal artifact: Kuhn -> クン, and the army 軍 examines the metal 金 object.