Guardrail, Handrail, Bannister
noun
A column made of dry wood is turned into a guardrail to help people walk up and down stairs.
らんかん
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
その欄干は古いからもたれないほうがいい。
This guardrail is old so you shouldn’t lean on it.