<span>Homonyms are words with the same pronunciation, but they hold different meanings. An example of two homonyms are "dear", used to refer to someone close to oneself, and "deer", which is an animal. Other examples of homonyms are "there", "their" and "they're".</span><span />
I believe that you should definitely set your own example by not laughing or deriding that other student. If they do something wrong, you shouldn't laugh at them or mock them, but rather try to help them. What you can do as well is ask that other student nicely to stop deriding other students because of a mistake they may have made.