1.
guy; fellow; man
A rough, informal word for a man or boy. Used among men in casual settings, sometimes affectionately.
Register
野郎 is a strongly masculine, rough word. It is used almost exclusively by men. Women rarely use this word except in very casual or deliberately rough speech.
Usage
The tone determines whether it is affectionate (sense 1) or hostile (sense 2). Among close male friends, it can be used playfully. Directed at strangers or enemies, it is an insult.