starch

(noun) 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. Synonyms: amylum.

(noun) a commercial preparation of starch that is used to stiffen textile fabrics in laundering.

(verb) stiffen with starch. Example: "Starch clothes."