I know that some moms thought this was a terrible idea, but I am finding that my kindergartener loves big words and his teacher sends a list home each week. We just read the word and the sentence at the dinner table (for the benefit of the two older kids), and let our youngest tell us what he thinks the word means. It’s actually a cute and fun exercise and he’s surprisingly correct most of the time. Try it. Your older kids will be DYING to give the answer. And that doesn’t suck!
Kindergarteners do have the ability to understand and really enjoy learning big, fancy words. It makes them feel like big kids. It was fun also to see his big sisters chomping at the bit to define “his” words.