That's how I understood it, too. The basic article on the word materialism on Wiki is more-or-less what I do and have understood about it for a long, long time. The first sentence on Wiki in connection with it reads:
Materialism is a form of philosophical monism which holds that matter is the fundamental substance in nature, and that all phenomena, including mental phenomena and consciousness, are the result of material interactions.
Now, I don't really know what exactly philosophical monism entails; only that it's philosophic.
To me the word materialism basically is a word lots of YEC's spurn out as a swear-word every few seconds. They use it for anyone who doesn't believe in a 6-day creation a few thousand years ago...