Sentence:  <WSD>Pannier</WSD> literally means carrying bags slung over the back of a beast of burden — in other words, saddle bags. Front and rear bicycle touring <WSD>panniers</WSD>, after being attached to their carrying racks on the bicycle, become the bicycle tourist's packbags. 
Meaning of the word marked with <WSD> tags:  A large basket or bag fastened, usually in pairs, to the back of a bicycle or pack animal, or carried in pairs over the shoulders.