In your first sentence, I think you meant "preposition", not "proposition", so something like "bag of gold" should work.
In the code example, I didn't notice that you had included the adjective as a prefix to the object name, so I went looking for an adjective property. It doesn't show up with Ctrl+Space, but I guessed it to be adjective = "tongue" inside the object definition. Both methods work, providing you still supply a noun in the command. If you use a command like X ADDER'S TONGUE (without FERN), it still refers to the hound's tongue.
Can I somehow define multiple adjectives?