Update: This meaning was added in January 2021.
If you watched the 2020 Olympics and were on Twitter, you likely know that comedian Leslie Jones was posting her own commentary. The universal consensus: Leslie’s commentary was lit.
Older Slang Use of Lit
The slang word lit has a long history. Its earliest meaning is “intoxicated,” a use that dates back as far as the early 20th century:
We walked into the vamp's house. We all got lit and had a hell of a time. — John McGavock Grider, War Birds: Diary of an Unknown Aviator, 1918
This particular use of lit is tied directly to the illuminating one, from the past tense of the verb light. Lit has long described something that is illumined or has light shining on it. The “intoxicated” meaning is less of a semantic stretch than one might think: lit and lit up are often used to refer to the look on someone’s face when they are suddenly made happy by something, and there’s no denying that many people feel or look similarly happy when under the influence of alcohol.
Though the "drunk" meaning of lit has a pedigree stretching back over a century, it is still considered slang: it appears primarily in informal settings (primarily speech and rap lyrics) and doesn’t have the same sort of all-purpose application that drunk does. But unlike many other century-old slang terms, lit in its "intoxicated" sense has seen a resurgence in use among a new generation of youth thanks in no small part to rap.
New Meaning of Lit
We can also thank rap for breathing new meaning into the word. In the 2010s, lit transitioned from the experience of becoming intoxicated ("gonna get lit") to the environment of those who are so lit ("this party is lit"). The excitement of such parties has led to lit gaining the meaning "exciting," as well as a broader meaning along the lines of "excellent" ("Leslie Jones's commentary on the Olympics was lit").
Unlike the earlier "intoxicated" sense, this meaning is just starting to make the leap from personal messages to edited prose. Chances are, though, that it's lit enough to be fully adopted.
Words We're Watching talks about words we are increasingly seeing in use but that have not yet met our criteria for entry.