A Safe
Safe
noun
Gold storage is where you put your gold. You want it to be safe, so you put it in a safe.
きんこ
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
彼が私の金庫を盗んでいた時、私はその物音が聞こえないふりをしていました。
I pretended not to hear him when he stole from my safe.