v. & n.
—v. (past and past part. cost)
1 tr. be obtainable for (a sum of money); have as a price (what does it cost?; it cost me pound50).
2 tr. involve as a loss or sacrifice (it cost them much effort; it cost him his life).
3 tr. (past and past part. costed) fix or estimate the cost or price of.
4 colloq. a tr. be costly to (it'll cost you). b intr. be costly.
1 what a thing costs; the price paid or to be paid.
2 a loss or sacrifice; an expenditure of time, effort, etc.
3 (in pl.) legal expenses, esp. those allowed in favour of the winning party or against the losing party in a suit.
Phrases and idioms:
at all costs (or at any cost) no matter what the cost or risk may be. at cost at the initial cost; at cost price. at the cost of at the expense of losing or sacrificing. cost accountant an accountant who records costs and (esp. overhead) expenses in a business concern. cost-benefit assessing the relation between the cost of an operation and the value of the resulting benefits (cost-benefit analysis). cost (or costing) clerk a clerk who records costs and expenses in a business concern. cost a person dear (or dearly) involve a person in a high cost or a heavy penalty. cost-effective effective or productive in relation to its cost. cost of living the level of prices esp. of the basic necessities of life. cost-plus calculated as the basic cost plus a profit factor. cost price the price paid for a thing by one who later sells it. cost push Econ. factors other than demand that cause inflation. to a person's cost at a person's expense; with loss or disadvantage to a person.
Etymology: ME f. OF coster, couster, coust ult. f. L constare stand firm, stand at a price (as COM-, stare stand)

Useful english dictionary. 2012.