1. A place where a man can go to get away from the world, more generally a place where your wife and your mistress are not. It can be a permanent structure such as a special room in the house (commonly a basement)or could be the fishing boat.
2. An area or activity that men congregate to let it all hang out with out being called disgusting. A place where men can freely scratch their balls, burp, fart and use foul language without having to worry about who they will offend.
3. A location where a man can be alone without certain distractions and gather his thoughts.
1. After a 60 hour work week, Geoff decided to retreat to his mantuary. That way he would not have to listen to his wife Elisabeth bitch about the lawn.