Any company that creates a product similar to other existing products and offers it at no cost to the users, causing other companies to fail due to the difficulties of offering products for free.
Google is a Googlopoly because, alot of their products like for example their google maps for android, is hurting other companies stocks because the product has almost all the same features and more that the competitors have, but for the lowest price possible, free!
Googlopolies are good and bad, almost equally good and bad. They are good because it causes competition to lower their prices, it also makes it so we can get great products free.
But it's bad because competitors can't make money, which knocks them out of business!