The command is:
#rm -r /directory/path
WARNING: Issue a 'pwd' command first to make sure you are in the parent directory of the directory you want to delete. Either that or put the full pathname of the directory in the command above.
You may find that you will get prompted for each and every file. If so, issue:
#rm -rf /directory/path
instead. It will force the command and not prompt you for anything.
Remember, there isn't any undo function, so use this one with caution.