Wordnet 3.0
NOUN (1)
1.
a fortress established in the southwestern United States by the Spanish in order to protect their missions and other holdings;
- Example: "Tucson was first settled as a walled presidio"
The Collaborative International Dictionary of English v.0.48:
Presidio \Pre*si"di*o\, n. [Sp.]
A place of defense; a fortress; a garrison; a fortress; a
garrison or guardhouse.
[1913 Webster]
WordNet (r) 3.0 (2006):
presidio
n 1: a fortress established in the southwestern United States by
the Spanish in order to protect their missions and other
holdings; "Tucson was first settled as a walled presidio"