Sentence:  One moment , the road was filled with disciplined troops , marching four by four with a <WSD>purpose</WSD> 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:  an anticipated outcome that is intended or that guides your planned actions