The gas station announced rollbacks on fuel prices due to the drop in oil costs.

rollbacks 是名词 rollback 的复数形式。rollback 由动词 roll（滚动）和 back（向后）组成，字面意思是"向后滚动"，引申为"回调、回退"的意思。在这里指燃油价格的"下调"或"回调"。