If an increase in price for a product results in a big decrease in Qd for that product,

we say demand for that product is

equilibrium

Explanation:

If there is a decrease in supply of goods and services while demand remains the same, prices tend to rise to a higher equilibrium price and a lower quantity of goods and services ... However, when demand increases and supply remains the same, the higher demand leads to a higher equilibrium price and vice versa.