How do you define a business flop? We all have a broad idea of how to gauge failures and successes, but when it comes to a company such as Apple (AAPL), what constitutes a flop can be very different compared to everyone else.

Flops can be poorly designed products, an offering that failed to sell, a PR nightmare or a combination of some or all three. However, when you're one of the largest companies in the world, your measure of success on those fronts changes considerably. What might be deemed a monumental venture from a lesser-known company could be perceived as an abject disappointment at Apple because it doesn't meet what we've come to expect after its decades of technological brilliance.

Here are some of Apple's biggest flops in its 43-year history. While Apple has churned out a litany of blockbuster products such as the iPhone, iPad, iPod and MacBook, the company has taken risks to get those big wins ... and they didn't always pay off.

20th Anniversary Mac

Courtesy Apple

Apple recently celebrated the 35th anniversary of the Mac. The occasion was marked by a tweet from CEO Tim Cook, but past that, there was little fanfare out of Cupertino, California.

Perhaps that's because of bad memories still lingering from