When the average kinetic energy of the molecules goes up (a rise in temperature), the average speed of the molecules increases. And lower average kinetic energy of the molecules means they have lower speed. However, a change in average kinetic energy is not directly proportional to a change in average speed. 1.
An appreciation means an increase in the value of a currency. It means a currency is worth more in terms of foreign currency.
Appreciate is defined as being grateful to someone. An example of appreciate is if someone helps you move and you thank them for their help. Appreciate is when the price of something goes up. A savings account that earns interest is an example of a savings account that will appreciate over time.