These potato chips are so crispy that they make a crunching sound when you bite them.

crispy 是形容词，来自名词 crisp（脆的、易碎的东西），加上后缀 -y 变成形容词，表示"酥脆的、脆的"，常用来形容食物经过油炸或烘烤后变得松脆的口感。