what is materialistic in ai behavior?

I live in a country where I don't speak English, and the word materialism is understood as having fun looking for things, being greedy, etc. In other words, I thought it was selfish, but I can't feel it's much different from aggressive ai in real games.

What trend does materialistic ai have?

It means they try and pick up items aggressively, so instead of saving healing items for when they're needed they'll grab them even at full health.