Antonyms of connoisseur:
groundling, lowbrow, materialist, philistine, apprentice, beginner, neophyte, novice, dabbler, dilettante, layman, nonprofessional, amateur, inexpert, nonexpert.
Examples of usage:
  1. For all that, he poured out a liberal measure of whisky and drank slowly, like a connoisseur.
  2. He 's a connoisseur.
    "Roderick Hudson", Henry James.
  3. They were all good, and his delight in them was plain; but he was evidently in no sense a connoisseur beyond that of natural instinct.
    "The Pool in the Desert", Sara Jeanette Duncan.