1. A large deep brass serving dish with a lid: Barbara's grandmother had a large tureen for serving soups and stews for dinner.

In earlier days the brass serving tureen was called a "terrene"..
2. Etymology, about 1706, from French terrine "earthen vessel".

About 1412, from Old French therine,

Also from terrin (adj) "earthen", from Gallo-Romance terrinus-

And from Latin terrenus "of the earth".

The spelling with u may be an everyday equivalent to e before r and is said to have arisen in cookbooks.