Sentence:  A dozen cows mooed sadly and regarded us as if we were insane , as perhaps we were at that moment , with the crazy excitement of our first encounter , the yelling and shooting still continuing up at the road , and the thirst of some of the men , which was <WSD>so</WSD> great that they waded into the muddy water and scooped up handfuls of it . 
Meaning of the word marked with <WSD> tags:  to a very great extent or degree