arrowroot: a nutritive starch obtained from the root of the arrowroot plant
starch: a complex carbohydrate found chiefly in seeds, fruits, tubers, roots and stem pith of plants, notably in corn, potatoes, wheat, and rice; an important foodstuff and used otherwise especially in adhesives and as fillers and stiffeners for paper and textiles
ratchet wheel: toothed wheel held in place by a pawl or detent and turned by a lever