LAW

(PRINCIPLE) [noun] [C] - a general rule which states what always happens when the same conditions existNewton's laws of motionThe first law of (= the most important principle in) politics is - if you're going to lie, don't get found out!See also Murphy's law; Parkinson's law.The law of averages is the belief that if something happens often then it will also happen regularly.If you toss a coin a hundred times, the law of averages suggests roughly fifty will come up heads and fifty tails.The law of supply and demand is the idea that the price of goods and services depends on how much of something is being sold and how many people want to buy it.When there's a lot of unemployment, wages stay low - it's the law of supply and demand.