Lascīvus ("wanton") looks to me like it comes from a verb, with the -sc- and the -īv-. However, I don't know of any verb like *lascō. Lewis and Short connect it to other words starting with la- meaning everything from "play" to "behold" to "plentiful", but that makes it hard to see any connection between them.
Where does this word actually come from? And what was the original meaning of its root?
