Deflate, inflate, and what about flate?

Yesterday in the van Kendra asked, "Mommy, I know what deflate means. But what's the opposite of that? Is it flate?"

And, in case you're wondering, yes it did absolutely remind me of the movie 10 Things I Hate About You where Bianca's friend asks her, "I know you can be overwhelmed and underwhelmed, but can you ever be just whelmed?"