Jōyō kanji, Taught in junior high
JLPT level: N1
968 of 2500 most used kanji in newspapers
Stroke count: 15
Meaning: penetrate, clear, pierce, strike home, sit up (all night)
Kunyomi:
Onyomi: テツ
Composition: 彳
Radical: 彳
Meaning: step
徹夜 （テツヤ） staying up all night
徹カラ （テツカラ） all-night karaoke
冷徹 （レイテツ） cool-headed, level-headed, hard-headed
透徹 （トウテツ） penetration, absolutely clear, not dirty, clearness