Does anyone know of a good online game or website where we can introduce DD9 and DD7 to some new vocabulary? Nothing too wildly advanced, mind you.

We were reading A Wrinkle In Time together and the word agog came up, which neither daughter had ever heard of, so I had them guess at the definition and then we looked it up. Their guesses were surprisingly good and we decided we would do some vocab this summer. A Wrinkle In Time is a good start for them since it does have a lot of words that they will probably not know the definitions of, but I was hoping for something else for when we are done with the book.

I was initially thinking about signing up for a "word of the day" type email and I found something for that, but I'd really like to to find a game or website that delves more into the etymology of the words. I would like it to be more game-like and fun and not just words with definitions. Hopefully someone might have some suggestions for us.

www.freerice.com

https://www.vocabulary.com is excellent (and free).

'agog' entry:
https://www.vocabulary.com/dictionary/agog?family=Agog

Try the tab 'challenge' - it will teach you words, test you in various ways (which is part of teaching), keep track of your progress, choose words to be learned based on it. Create separate accounts for you and your child. You can specify which words to learn too. One good list is https://www.vocabulary.com/lists/52473#view=notes 'vocabulary.com top 1000 words'.

Personally, I always found it much easier to absorb new language via books or casual conversation, as opposed to attempting to just study/memorize it.

I'm sure there are plenty of online sites out there, though.

I keep meaning to get one of thsoe "word a day" calendars. I know a homeschooling mom who just puts a couple of words and their definitions on a whiteboard every day. I'd like to see DD improve her vocab a little, too. For some reason it seems to be a weaker area for her, and I think it holds back her reading understanding a little. She's great on things like theme and understanding characters, but sometimes she'll miss a question because she doesn't know a word.

Not a website, but the leveled series of books "Words are Important" is excellent. You could probably pick up a used copy inexpensively.

Online: The NYT word of the day is free.

http://learning.blogs.nytimes.com/category/word-of-the-day/

Many years ago, I took the GRE. I used vocabulary cards to learn more vocab. Then, years later I bought a Word of the Day calendar. Many of the same words were on both.

The Word a Day calendar has lots of history about the words.