Command Syntax:
gpasswd -d user_name group_name
Change user_name with your actual system user name and group_name with named of group from which you want to remove user.
Example
Use the following command to remove user jack from sysadmin group.
gpasswd -d jack sysadmin
Add User to Secondary Group
The following command will will add user jack to a secondary group named sysadmin.
usermod -aG sysadmin jack
Since you used the command gpasswd .how can we get confirmed about it??
you didnt mention any steps for that??????
You can verify the groups the user is a member of or the ones the user was removed from by running
# id
after running the
# gpasswd -d
command.