Sentence:  Frustrated, rushed, you toss the <WSD>saddlebags</WSD> filled with textbooks, ungraded papers, and drafts of poems onto the back of your cruiser motorcycle and roar off down Ambler not thinking speed and a strong crosswind will lift the <WSD>saddlebags</WSD> into flight like some leather-winged prehistoric bird hanging in the air a second before flopping onto the busiest street in North Abilene. 
Meaning of the word marked with <WSD> tags:  A covered pouch, usually one of a pair, laid across the back of a horse, donkey, or mule behind its saddle, or hanging over the rear wheel of a bicycle or motorcycle; often made of leather or (on a bicycle or motorcycle) a rigid material.