I re-read Tolkien as an adult and was like, "I don't remember having to look up so many words when I was a kid!" And it's because kids are used to not knowing all the words and having to glean their meanings from context. It's ADULTS who find unfamiliar words a stumbling block
Rachel Hartman
Those were unnecessary. Kids can use context cues. Kids can look things up. If you really think they won’t understand something without knowing that word, put in a footnote. That’s how they learn about other cultures!