This is a reference to the Native American word caoutchouc, meaning the sap of a rubber tree.
It would seem that in Lyra's world, the word "cahuchuc" means rubber and/or possibly plastic.
The word nälkäinen comes from Finnish and means "hungry".
According to Tony Costa, the Nälkäinens are a kind of ghost that exists in the North. However he also tells Lyra that Tartars eat children, of which we never see evidence, so it's up for debate whether the creatures really exist or are the product of myths or fairytales.
Tony also mentions another nightmare creature called "Windsuckers". In the second and third books in the trilogy, The Subtle Knife and The Amber Spyglass respectively, Lyra encounters creatures called Spectres that seem to share some of their characteristics.
This is an example of the Dutch that has seeped into the language of the Gyptians by way of the Fens. The word landlopers literally means "land-walkers" in Dutch.
A sovereign was a coin worth about one pound sterling, or twenty shillings, although the coins had no value marked on them. They were first produced in 1489, and are still made today.
If Lyra's world has a currency value similar to the Victorian era, the price on Lyra's head is a large one.
European eels (Anguilla anguilla) are freshwater eels, often eaten as jellied eels or glass eels.
For the more adventurous chefs amongst you, a recipe for fried eels can be found here. Go on, I dare you.