弐
ニ, ジ, ふた.つ, そえ
II, two, second
JLPT1 G7 S6 F5000
Originally 弍: 弋 stake + 二# two → *two* stakes aligned side by side. As with 壱, 参/參, and 拾, this character is used as a substitute for the usual number (in this case, 二) in documents as a precaution against forgery.
[Full Kanji Etymology List]