Weak Currency
  
A currency is only weak when compared to its fellow currencies. A weak currency is a currency that has gone down in value compared to other currencies. Depending on which way you’re converting your money, a weak currency can be good (allowing you to buy more value) or bad (decreasing your buying power).
In general though, weak currencies are bad for the residing nation. Weak currencies often come from inflation issues, deficits, high imports compared to exports, and slow economic growth. The better a country’s economy is doing, the less likely they are to have a weak currency.
While weak currencies are usually the result of normal economic ups and downs, they can also be the result of larger events (Brexit, anyone?) and may even be purposefully implemented after a long period of currency strengthening (looking at you, China circa 2015).