The gain that occurs when one exchanges one floating currency for another, then back into the first currency after it has become weaker. For example, suppose one has 1,000,000 U.S. dollars and exchanges them for 500,000 British pounds; this means the exchange rate was two dollars per pound. Later, if one still has those 500,000 pounds when the exchange rate is three dollar per pound and exchanges them back to dollars, suddenly one has $1,500,000. In this case, the translation gain is $500,000.
The gain that results when a firm translates amounts stated in one currency into terms of another currency. A U.S. company that translates German marks into U.S. dollars following a period of a weakening dollar will report a translation gain because the marks exchange for a greater number of dollars.