Unman Definition

unmanned, unmanning, unmans
To deprive of manly courage, nerve, self-confidence, etc.
Webster's New World
To take away characteristics traditionally associated with masculinity, such as courage or strength.
American Heritage
To emasculate; castrate.
Webster's New World
To deprive of men or personnel.
Webster's New World

To sap the strength, whether physical or emotional, required to deal with a situation.

His fear unmanned him.