When JRR Tolkien wrote the Lord of the Rings he didn’t just give his characters any name he felt like.
All the names of people, things and places come from real people, old languages, or languages that he made himself. He used Old Norse, Old English and Finnish, as well as making up several Elvish languages, Orcish and many others.

Here is a list of just a few words and their roots:

Frodo: from Frodi, a Norse King.

Sam Gamgee: Dr Sam Gamgee lived near Tolkien and invented a type of medical cotton wool.

Gandalf: from Old Norse, it means elf with a staff.

Aragorn: from Sindarin, an elvish language Tolkien made up, it means King-Tree.

Sauron: from Old Norse, it means abominable.

Saruman: from Old English, it means cunning man.

Legolas: from Sindarin, it probably means green-leaf

Galadriel: from Sindarin, meaning tree-daughter

Mordor: from Old English, it means murder or mortal sin

Theoden: King of Rohan, his name means King or Lord of Men

Edoras: capital of Rohan, it means enclosures.

Grima: he is a bit suspicious and his name means mask.

With thanks to Dr Thomas Shippey.