Risk: The possibility of gain or loss. Risk the calculated probability of different events happening, is usually contrasted with uncertainty the possibility that any number of things could happen. For example, uncertainty is the possibility that you could win or lose $100 on the flip of a coin. You don't know which will happen, it could go either way. Risk, in contrast, is the 50 percent chance of winning $100 and the 50 percent chance of losing $100 on the flip of the coin. You know (or think you know) that your probability of winning or losing is 50 percent because the coin has a 50 percent chance of coming up either heads or tails.
Recession: The common term used for the contraction phase of the business cycle. A general period of declining economic activity. During a recession, real gross domestic product declines by 10 percent or so and the unemployment rate rises from it's full employment 5 percent level up to the 6 to 10 percent range. Inflation tends to be low or non-existent during a recession.
trade deficit: Formally termed a balance of trade deficit, a condition in which a nation's imports are greater than exports. In other words, a country is buying more stuff for foreigners than foreigners are buying from domestic producers. A trade deficit is usually thought to be bad for a country. For this reason, some countries seek to reduce their trade deficit by--(1) establishing trade barriers on imports, (2) reducing the exchange rate (termed devaluation) such that exports are less expensive and imports more expensive, or (3) invading foreign countries with sizable armies.
Bull market: A condition of the stock market in which stock prices are generally rising and most of the participants expect this to continue. In other words, the stock market is into an extended period of "charging ahead" like a mad bull. A bull market usually occurs because investors see a healthy, vibrant, profitable economy on the horizon.