valley. (building construction). An inside angle formed where two sloping sides intersect. (geography). A generally broad area of flat, low-lying land bordered by higher ground.
In ordinary usage, price is the quantity of payment or compensation given by one party to another in return for goods or services.
Definition of cost for English Language Learners. : the price of something : the amount of money that is needed to pay for or buy something. : an amount of money that must be spent regularly to pay for something (such as running a business or raising a family)