At my grandma's house, there were two small rooms off of the cellar. One was called the coal cellar because that is where the coal for the furnace was kept. The other was called the fruit cellar. Unlike your root cellar, it didn't have a special kind of door and the floor was concrete. It always smelled musty and like rotten apples. It was really an odd smell, unlike anything else. It don't recall the fruit cellar really being used, but it probably was used a lot when my grandparents were younger and grew a lot of fruit.
So I'm wondering, is "fruit cellar" a term used in certain parts of the country, or just a term my family made up, maybe a corruption of root cellar?
In my part of the country the Fruit Cellar and the Root Cellar were interchangeable words...both meant the same thing, just depended what was being placed in it at the moment.
When they gave me apples to take down there, they sent me to the fruit cellar.
When they sent me into that same dark room with potatoes, it was the root cellar.
However, my other grandmother had the same underground space, and the fruit cellar was behind the root cellar, with some sort of divider between (which I can't remember clearly enough to tell you what it was.) Then the coal cellar was on the other side, and it was not connected to the other two.
Does that make sense?
When one grandma said take it to the fruit cellar, I took it to the one big room under her house. But when the other grandma said take it to the fruit cellar, I had to go through the root cellar to get there. And if either of them said bring a bucket of coal back with you, then I had to leave the root/fruit cellar, go around to the other end of the house, to get to the coal cellar.
Much more info than you wanted to know, but you are right with the name.