Abarim Publications' online Biblical Hebrew Dictionary
אצר
The verb אצר ('asar) means to store or lay up, of treasure (2 Kings 20:17, Amos 3:10) or merchandise (Isaiah 23:18). This sparsely used verb yields only one derivative, which occurs about eighty times in the Bible: the masculine noun אוצר ('osar), meaning treasure, treasury (Joshua 6:19, 1 Kings 7:51, Psalm 33:7). It's one of nine Hebrew words that are used in the Bible, which denote a depository of goods.