declining
v.v. becoming smaller, fewer, or less successful. You use this to describe things like health, prices, or the number of people in a group going down over time.
v. gradually decreasing in number, strength, or quality; moving toward a lower state or level. Often used in formal or academic contexts to describe statistical trends or physical deterioration.
The number of local birds is declining every year.
Economists are worried about the declining birth rate in several developed nations over the last decade.
The historian argued that the empire's declining influence was not due to a single defeat, but rather a century of internal corruption and economic stagnation.
Often used as a present participle ('declining') to function as an adjective before a noun. When used as a verb, it can be intransitive or transitive (meaning to politely refuse).
The prices are declining down.The prices are declining.Declining already means moving down; adding 'down' is redundant.