Sentence:  One moment , the road <WSD>was</WSD> filled with disciplined troops , marching four by four with a purpose as implacable as death ; the next , a cloud of gun smoke covered a screaming fury of sound , out of which the redcoat soldiers emerged with their bayonets and their cursing fury . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)