si·lo 
(sīlō)
(sīlō)n. pl. si·los
1.
a. A usually tall cylindrical structure, typically next to a barn, in which silage is produced and stored.
b. Any of several other structures or containers used for the same purpose, such as a covered trench or a polyethylene bag.
2. An underground shelter for a missile, usually equipped to launch the missile or to raise it into a launching position.
tr.v. si·loed, si·lo·ing, si·los
To store in a silo.
[Spanish.]