Fort
Part of speech: noun
Definition: A fortified defensive structure stationed with troops Any permanent army post
Example sentence: I'm originally from Fort Lauderdale: that's my home town in Florida. So when I'm on location, I just get the packets from schools in Florida. And when I go to Florida, I go to Christ Church School.
Fortress
Part of speech: noun
Definition: A fortified place; a large and permanent fortification, sometimes including a town; a fort; a castle; a stronghold; a place of defense or security.
Part of speech: verb
Definition: To furnish with a fortress or with fortresses; to guard; to fortify.