cost

1 cost /ˈkɑːst/ noun
plural costs
1 cost
/ˈkɑːst/
noun
plural costs
Britannica Dictionary definition of COST
1 
: the price of something : the amount of money that is needed to pay for or buy something
[count]
[noncount]
Synonyms see: [1]price
2 
[count] : an amount of money that must be spent regularly to pay for something (such as running a business or raising a family)
— usually plural
— see also cost of living
3 
: something that is lost, damaged, or given up in order to achieve or get something
[noncount]
— often used after at
[count]
◊ To do something at all costs or (less commonly) at any cost is to do it even if you have to suffer, work very hard, lose everything you have, etc.
4 
costs [plural] : the money used to pay for a court case

at cost

US
◊ If you buy or sell something at cost, you buy or sell it for the amount of money that was needed to make it or get it.

at no cost

— used to say that something is free

count the cost

— see 1count

to your cost

chiefly British
: from your own bad experience
2 cost /ˈkɑːst/ verb
costs; cost; costing
2 cost
/ˈkɑːst/
verb
costs; cost; costing
Britannica Dictionary definition of COST
[+ object]
1 
a  : to have (an amount of money) as a price
◊ If something costs a certain amount of money, you have to pay that amount of money in order to buy it, use it, or do it.
b  : to cause (someone) to pay an amount of money
◊ If something does not cost (you) a penny or (US) cost (you) a dime/nickel, you do not need to pay any money for it; it is free.
2 
a  : to cause (someone) to lose something
◊ If something costs you dearly/dear, it causes you to lose something or to suffer a lot.
b  : to cause (someone) to experience something unpleasant
3 
British, business past tense costed : to determine how much money will be needed to pay for (something) — usually used as (be) costed
— often + out — see also costing