Here is a Wikipedia definition, of something that must happen before something else happens, but I'm not sure how to apply it to the law.
Let's say that there is an angel investor that meets a company with an interesting technology, and proposes to invest an amount, X, in the company for a certain percentage. The contract says something like, "a condition precedent for the investment of X is a demonstration of the company's technology to the investor's reasonable satisfaction." The company delays in doing the demo, but asks for the money. The investor says, "no demo, no money." Is this what "condition precedent" is meant to say?
If there is no express time limit written into the contract, is there an implied, or "reasonable" time limit after which the investor is off the hook? For instance, if the demo took place six months later, can the investor reasonably say, "your technology sounded interesting six months ago, but I fear that it has been made obsolete by now."