I’m writing an essay on my peculiar interest in mathematics, so my essay is centered around a mathematical meme that I created and sent to a Facebook page that later posted it. Would it be safe to use the word meme without defining it, or would I be better off not writing about it at all (I don’t want a definition to make the essay too wordy)? This is for my Why UChicago essay.
You don’t need to define meme. I’m old, so I can assure you it is part of the popular lexicon beyond your age group.
In my 50s and know what a meme is. I think you’re good. 
Ditto.
What’s facebook??
(jk)