Færie is the name of the homeland/city of the "Færie People" in JRR Tolkien's "Tree and Leaf", a little known collection of his early short stories, written years before the ubiquitous "Lord of the Rings".
In reality the word is dated back to around 1590 and comes from the Middle French form of the word "fairy", but is often used to denote a greater seriousness of character and power upon the "Fair Folk" or "Fay People".
Also used for preference by Neil Gaiman in the Sandman series of graphic novels, as well as by multiple other fantasy writers of varying ability.
The implication is usually that if you were to run across a fairy out in the countryside you could possibly be annoyed by a tinkling, darting moron with all the threatening capacity of a slightly magical mosquito.
If you bumped into one of the færie however, you'd be more likely to be found the next morning wearing your intestines like a garland.