段
だん · dan · JLPT N3 · noun
measure
🪜🥋 Same dan as a black-belt grade: 1st dan, 2nd dan, each one a step up
In judo and karate, ranks are counted in dan, which is this kanji. The right side 殳 means a hand holding a tool, so you can read the whole character as cutting steps into rock. The steps of a staircase and the grades of a rank both go up one 段 at a time.
段 — left component 𠂉 + right component 殳 (weapon/strike)
段 originally depicted striking or hammering a piece of stone or metal with a tool, shown by the 殳 'strike' element on the right. From this 'hammering/forging' sense it extended to mean a section or segment cut off, and today it commonly means a paragraph, stage, or piece.