How Override naming conventions for mongodb document

Model for MongoDb looks like follows

class User   include MongoMapper::Document   key :name, String end

Name of the table in MonoDb is users.

How to override naming convention for MongoMapper::Document ?

Why do you want to rename it in the first place? Name convention is there for a reason - I think you're on a slippery slope there. You can rename your class, obviously.