iron rust; iron hydroxide
Refers to the reddish-brown substance formed on iron when it oxidizes; also used in chemistry for iron hydroxide (水酸化鉄).
See also: 水酸化鉄 (すいさんかてつ)
Iron rust had formed on the old iron bridge.
Iron rust is also called iron hydroxide.
Common mixed kanji-kana spelling; clear and easy to read.
Full kanji spelling; 錆 is a less common character and may be harder for learners.
Compound of 鉄 (てつ, 'iron') and 錆 (さび, 'rust'). The reading さび is the native Japanese word for rust.