Know what? We need to stop talking down to kids.
It's easier today than ever before to look up a word, by using dictionary.com.
We're all so worried about being too smart for kids, and in the process, we're dumbing down America/the world.
Just write it.
(ps not intentionally crabby, and any apparent crabbiness is not directed at the OP... I just came in here and have read several threads about 'what we should and shouldn't do' to be politically correct in MG and YA. Sheesh!!! Everybody needs to go read "To Kill a Mockingbird" again, and realize THAT story is told from the POV of a 6-8 year old, and involves rape, racism, crime, murder, and a hell of a lot of big words. That book today? From an 8-year-old POV? Would be considered MG or maybe YA, according to the new standards of publishing. Sometimes I wish there weren't so many categories, and so many rules. Back when TKAM was published, there was no such thing as YA. It was an adult book, but people of all ages read it. My kids LOVED it at ages 7 & 10, just as I loved it the first time I read it, in high school.)
People, please stop fretting. Kids today deal with much worse stuff than we ever did. They can handle it, and they can handle big words. Just write.