Oh boy, do I hate how society makes up new words and phrases to seem cool, hip, and special to their peers. Here are ones I can't stand hearing.
1. Womyn: Boy, I hate this word. Why does this exist? Why do you want to remove an E from a word because it makes the word contain "men"? You have to be quite a misandrist to want to change the spelling just due to that. What is wrong with having "men" in the word "women?" Nothing. Trust me this about as pointless as renaming the human species "Hetro-sapien" because "Homo-sapien" has the word "Homo" in it.
2. White-tears: This word is used as a meaning saying "It is only something that only whites cry/worry about." This word is usually vomited at someone that is pointing out racism against whites to someone that is the racist spewing this garbage. White racism is no better or worse than any other form of racism. Racism is bad no matter who its being thrown to.
3. Otherkin: I don't just hate the word, I hate the fact there are people on this earth who believe that there some sort of animal trapped in a human body. Nor I don't like the fact that otherkin doesn't only pertain to animals, it also goes for fictional characters and real people as well. These people will cry oppression if someone looks at them with a glare because they told someone that they're a dragon trapped in human form.
4. Yiff/Clopping: First off, these fetishes really shouldn't exist. Second, why do they need a special word for fucking or masturbating to their fetish? Give me one good reason why. Third, I understand how clop, means fap in brony language, but what action that isn't a hairy antro-dog dong strangling makes the noise "yiff." Assuming that yiff is a sound word like fap and clop.
5. Selfie: I really don't like how this word sounds in all honesty and all honesty is it really that hard to say self portrait? I especially hate the fact its meaning no longer means self portrait anymore, instead its a replacement for a picture, which doesn't make sense to me. Its like calling a biography an auto-biography.
6. Twerk: It is a more polite and trashy way of saying "Shaking ones rump like some amateur ghetto gutter girl. For some reason, people find twerking funny, I just don't get that.
7. "Everyone's perfect.": for some reason some special snowflake thought that the word "not" made the phrase "too offensive." By this sayings logic, everyone one is perfect, even Jeffery Dalmer and Adolf Hitler. Remember you're not perfect.
TL;DR: There's a reason why they aren't in a dictionary.