It may conjure images of Family Matters' bespectacled, suspenders-clad Steve Urkel. Or the theoretical physicist Sheldon Cooper from The Big Bang Theory. Or Scooby-Doo's Velma.

Or you may self-identify as a nerd due to your keen interest in a certain hobby or subject, like movies or grammar or whimsical parade floats.

Nerd has been part of our lexicon for at least three-quarters of a century, its geeky meaning embodied by some of the most recognizable characters in film and TV history. Still, how exactly it got into our vocabulary remains a bit murky.

"I've been making videos as the Etymology Nerd for a while, and so it's my job to know what the etymology of 'nerd' is," said Adam Aleksic, a linguist, content creator and author of the book Algospeak. "But the problem is that it's a little bit obscure. It's a very complicated story."