剣
ケン, つるぎ

sabre, sword, blade, clock hand

JLPT1 G7 S10 F1305

As per 僉# (assemble) + 刀 knife/sword → assemblage of blades in a double-bladed *sword*. The numerous variant forms include 剱, 釼, 劒 and 劔.

[Full Kanji Etymology List]