Sometimes it’s just so fun to look up the history of the most common words. The etymology of bad is one of those that has a few surprising twists and turns in it…and a bit of mystery, too.
Bad has been used in English forever, pretty much. It dates to around 1300 with the meaning of “inadequate, worthless.” By the 1400s, it could mean “evil, wicked, vicious.” Interestingly, though, it wasn’t a very common word. More often, people in fact used evil when they wanted that meaning, and that was considered the opposite of good. It wasn’t until the 1700s, in fact, that bad became the common opposite of good!
So…where did it come from? This one’s a little murky. Etymologists aren’t entirely certain, but their best guess is that it has its roots in the Old English baeddel…which was the word used for “effeminate man, hermaphrodite.”
It’s worth noting that a word that sounds the same and means the same in Persian evolved completely independently–and that Persian also has a word that sounds the same and means the same as better, but that one’s independent too! Always so fascinating when there’s an entirely coincidental cognate!
Okay, so the history of the definition is out of the way…now let’s look at some idiomatic uses. I was actually quite surprised to realize that bad has been used ironically as a word of approval since the 1890s! Historians think that likely evolved from racial tensions, actually. That White people would refer to “troublemaking” Black people as “bad”…but those same people were more like heroes standing up for their people to their people, so they used the same words but with approval.
It’s meant “uncomfortable, sorry” since 1839, not bad has been in use since 1771, and food etc has been going bad since the 1880s. (Okay, so the putrification still happened before that, it just wasn’t called “going bad,” LOL.)
Also noteworthy: badder and baddest were perfectly acceptable words all the way up into the 17th century! Shakespeare prefered worse and worst though, so I daresay we can credit him with those becoming “correct.”