Copernican is an adjective that means very important or paradigm-shifting.

Nicolas Copernicus was a 15th century astronomer who first observed that the planets revolved around the sun. Because this discovery was so significant, we use the word Copernican to describe highly important discoveries or innovations. For example:

My great grandfather made key discoveries about marine animals off the coast of Africa. Those discoveries aren’t talked about a great deal among the general public, but for those in his field, they were Copernican. They truly changed everything about what we know about marine animals.