Kevin was in disbelief. How could his parents leave without him?

disbelief: mental rejection of something as untrue
misbelief: erroneous or false belief
—Merriam-Webster

To keep these two words straight, consider this: Misbelief is when something is untrue. Disbelief is when you think something is untrue (regardless of whether it is). Disbelief tends to deal with thoughts and opinions. Misbelief deals with facts.

Examples
Ralph was in complete disbelief. He didn’t think Suzie could have stolen the lollipop.
It is a misbelief that George has three toes. He only has two.

It is a misbelief that the religion’s followers have to surgically attach octopus tentacles to their necks.
The leader stood in disbelief when he heard the rumor. “People believe that?” he asked.

Quiz
Fill in the blanks with either disbelief or misbelief. The answers are at the bottom.

1. No one thought Percy would finally propose. They were in _______ when Frank showed the ring on his finger.
2. You can believe a _______, but it will still be untrue.
3. When the kids explained that a dragon broke the antique lamp, their parents met the tale with _______.
4. It is a common _______ that Paul only eats sauerkraut after midnight. He usually eats it at seven p.m.

Answers:

1. disbelief 2. misbelief 3. disbelief 4. misbelief