verb

• (historical, UK) To deprive of the privilege of citizenship of a town or city.
  "But what punishment is laid vpon Recusants, by the rare clemencie of her Maiestie, any way comparable to those that Christian Emperours haue made against Recusants, or such as refused to communicate with the Church of Christ? They were discommoned from buying and selling, from bequeathing their goods or lands to others, or receiuing anie Legacies from others, yea they might not inioy their fathers inheritaunce, &c. What like thing is done to English Recusants? or rather what not vnlike? they buy, they sell, they bequeath their goods at their pleasure, they receiue legacies, and inioy inheritances."
• (historical, law) To deprive (lands etc.) of commonable quality, by enclosing or appropriating.
  "She saw in front of her a two-storey house, standing back from the gravel pathway, on the edge of a triangular piece of turf which represented, no doubt, a more extensive village green, now discommoned and taken in by the private dwellings scattered around."
• (transitive, UK, Oxford and Cambridge universities, historical) To deprive of the right to deal with undergraduates.
  "[…] persons violating the above statute are liable to a fine for the first offence, and to be discommoned for the second."