• 恒例こうれい — established custom; annual event
• 恒常的こうじょうてき — constant; continuous; steady
• 恒久こうきゅう — permanence; lasting
• 恒温こうおん — constant temperature
• 恒心こうしん — steadfast heart

The radical りっしんべん (heart) combines with the element 亘 (extend / span). Together, they suggest a heart or spirit that continues unchanged across time — expressing constancy, steadiness, and everlasting nature.