A Wiffle ball is a lightweight, plastic baseball that curves when you throw it right. Sure, you've played with them! Mental_floss has its origin story and the run down on the most pressing question you ever had about Wiffle balls.
What's with the name?
Like a lot of baseball fans, Mullany's son and his friends referred to strikeouts as "whiffs." Since the new invention made knee-buckling curveballs a breeze to throw, pitchers started racking up the punchouts. Mullany named the product the Wiffle Ball to honor its strikeout-friendly breaks.
Why no "h" if the ball is named after whiffs?
The Mullanys allegedly nixed the "h" to save money if they ever had to buy a sign for their fledgling enterprise.
You'll also find out about the serious sport of competitive Wiffle ball. Link