The word "nerd" has many meanings, some of them derogatory. It can mean an intellectual, someone who is socially awkward, someone who is very passionate about their interests, or a combination. On Happy Days, however, it is almost always seen as an insult, and it has a few extra meanings.
- In Fonzie's New Friend, Fonzie categorizes people into two types: cool and nerds. Here, he is defining "nerd" as "anyone I don't consider cool".
- In Fearless Fonzarelli: Part 2, Fonzie says, "I was a nerd to make that jump". Here, he is using "nerd" to mean "fool".