To Decay, To Become Weak, To Wither
intransitive verb, ichidan verb
Because the hiragana ends with an う sound, you know this word is a verb. The kanji itself means decline and the verb vocab version is to decline.
You're wandering through the jungle exploring, when you come upon a deep pit. Since you're looking for treasure, you decide to go down into the pit to look for some. You take out your handy auto rope (おとろ), made of organic, environment friendly materials, and easily rappel down into the pit. Unfortunately, you get lost down there, and it takes you fifty years to get back to the pit you came in from. But your auto rope is gone! This is the last time you buy an organic rope, made to decay and to wither away when left in the wild.
When I had this beef several years ago I was really impressed by how well it was aged and marbled, but the taste seems to have declined a bit and I’m really disappointed.