Definitions

1. verb

to fail or be unsuccessful in an examination or test, or to fail to meet expectations or standards

“She flunked her math test and had to retake it.”

2. noun

a bad or failing grade, especially on an examination

“Getting a flunk on her exam was a big disappointment.”

3. verb (informal)

to fail or be unsuccessful, especially in a particular activity or situation

“I flunked at trying to learn the piano.”