A boat is called a വള്ളം.
A cart is called a വണ്ടി.
Isn't it interesting that both start with വ?
That's not all. If you look deeper, you can see something more.
The underlying root for വള്ളം could be വള്് (just like the underlying root of വെള്ളം is വെള്് - white).
Using reverse ആദേശസന്ധി we can split വണ്ടി as
വണ്ടി = വള്് + തി
Thus we see the same വള്് here also!
If my above analysis is correct (and that is a big IF), വള്് can be thought of as the underlying root that means transportation, movement, etc.
The only other words that I can think of starting with വള്് are
- വള - bangle
- വളവ് - curve
- വളം - manure
- വളി - stale air (see previous post on this)
However, I would like to stick with this discovery until somebody proves it wrong :-)