noun
laundry starch
Starch used to stiffen clothes during washing; a household product.
ワイシャツに洗濯糊をつけると、パリッと仕上がる。
If you use laundry starch on a dress shirt, it comes out crisp.
糊 is the general term for starch or paste; 洗濯糊 specifically means laundry starch.
Compound of 洗濯 (laundry) and 糊 (starch, paste).