Overage, Obsolete, Too Old
Noun, する verb, and の adjective
ろうきゅう
その建物はかなり老朽しているので、立ち入らない方がいい。
That building is pretty decrepit so you shouldn’t go in it.
Elderly people start to decay and they get all decrepit and gross. Like a corpse. Bleh. Good thing I'll never be too old. Ho ho ho!
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.