A weak dollar refers to a downward price trend in the value of the U.S. dollar relative to other foreign currencies. The most commonly compared currency is the Euro, so if the Euro is rising in price compared to the dollar, the dollar is said to be weakening at that time. Essentially, a weak dollar means that a U.S. dollar can be exchanged for smaller amounts of foreign currency. The effect of this is that goods priced in U.S. dollars, as well as goods produced in non-US countries, become more expensive to U.S. consumers.