1. Thickness in English is referred to as "thick." 2. Thinness in English is referred to as "thin." 3. The term "thick" can be used to describe the粗细 of an object, as well as concepts such as density and opacity. For example: "For breakfast, I had a thick slice of bread with syrup." 4. The term "thin" is used to describe the slenderness of an object, as well as states such as being underweight or sparse. For example: "A thin cable transmits the signal to the computer."