English definition of “cost”
MONEY [C, U] › the amount of money that you need to buy or do something: The cruise ship was built at a cost of $400 million. Software is included at no extra cost. The cost of living (= the cost of food, clothes, etc) has increased.
SOMETHING GIVEN [no plural] › something that you give or lose, in order to get or achieve something else: He rescued four people at the cost of his own life.
at all costs › If something must be done at all costs, it is very important that it is done: We have to succeed at all costs.
to your cost UK › because of a bad experience you have had: An ankle injury can last a long time, as I know to my cost.