Sure, here's a list of neologisms from the past 15 years, ranked in order of their popularity and relevance:

1. Selfie - This term needs no introduction, as it has become one of the most ubiquitous words in the English language. It refers to a self-portrait photograph, typically taken with a smartphone camera.

2. YOLO - This acronym, which stands for "you only live once," became a popular catchphrase in the mid-2010s, used to justify impulsive or risky behavior.

3. FOMO - Short for "fear of missing out," this term describes the anxiety that arises from the feeling that others are having more fun or experiencing something more interesting than oneself.

4. Lit - This slang term is used to describe something that is exciting or enjoyable, often in the context of a party or social gathering.

5. Bae - A term of endearment that is short for "before anyone else," used to refer to a significant other or close friend.

6. Fleek - Meaning "perfect" or "on point," this term is typically used to describe a person's appearance or fashion sense.

7. Ghost - To suddenly cut off all communication with someone, without any explanation or warning.

8. Meme - Originally coined by biologist Richard Dawkins to describe the way cultural information is spread and evolved, "meme" has come to refer to humorous or viral images and videos on the internet.

9. Turnt - Similar to "lit," this slang term is used to describe a party or gathering that is energetic and fun.

10. Adulting - Used to describe the process of behaving like a responsible adult, particularly with regard to mundane tasks such as paying bills or doing laundry.

It's worth noting that this list is subjective and open to interpretation, and different people may have different opinions on which neologisms are the most "on fleek."
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