Erudite
We're using a five-dollar word to describe the style of Middlemarch because that's the kind of vocabulary Eliot uses for most of the novel. "Erudite" means extremely well educated, and that's what comes across as you read the novel. All the historical, scientific, cultural, and literary references the narrator makes contribute to the sense that you're reading a book by one heck of a smart woman – just check out the "Shout outs" section to see what a huge range of references Eliot makes. And that style is what earned George Eliot the reputation as a "Victorian Sage" – in other words, a writer who was educated and intelligent enough to comment on almost any aspect of contemporary life, from arts and literature to politics and science.