'Father,’ returned Joe, ‘I know what I say and mean, well—better than you do when you hear me. I can bear with you, but I cannot bear the contempt that your treating me in the way you do, brings upon me from others every day. Look at other young men of my age. Have they no liberty, no will, no right to speak? Are they obliged to sit mumchance, and to be ordered about till they are the laughing-stock of young and old? '

mumchance = bored or depressed. I have also seen it used to mean unable to speak up in self defence.