Wiktionary
n. a structure built underground or partially underground and used to store vegetables, fruits, and nuts or other foods
WordNet
n. an excavation where root vegetables are stored [syn: cellar]
Wikipedia
A root cellar is a structure built underground or partially underground and used to store vegetables, fruits, and nuts or other foods.
Usage examples of "root cellar".
The slug thumped into the root cellar door, which then creaked on its hinges.
The wind rattled the door of the root cellar, sending a small sifting of dirt down upon the cut-stone steps.
With a last glance at the root cellar door, she went back upstairs.
If I had been right that Duane's basement was originally a root cellar like my grandparents I would be able to get into it from the outside.
You'll have to help me with my last words, my wits have been running about like a rat in a root cellar.