/
ˈsʌɪləʊ/
n.
 (pl. silos)
   - a tall tower or pit on a farm, used to store grain.
 - a pit or other airtight structure in which green crops are compressed and stored as silage.
 - an underground chamber in which a guided missile is kept ready for firing.
 
Etymology
C19: from Sp., via L. from Gk siros ‘corn pit’.