In dictionary, Widow is a woman that left alone due to  her husband spent most of  his free time to his hobby or her husband was already passed away. Applying the similar concept, widow share is the stock that an investors can buy and left alone due to its strong fundamental and proper management.

 They are safe and won't become worthless paper even you didn't monitor it as it is very hard to fall drastically in value. Some investors even consider widow shares as 'true blue' or true blue chips. 

Normally, widows are those women that have no exposure to the finance world and was supremely ignorant of the complexities.Widow's share means those stock that can be invested by those widow with their eyes closed and sleep easy. In normal circumstances, widow's stock will distribute regular dividend although they are not paying the highest range of dividend in the market but they are also not volatile to the market too. The stock price does not rise or fall tremendously but bear a stable course.

However, since last few yeas, several of these "safe" companies have gone through difficulties, not able to distribute dividend and some have even gone bankrupt. The famous examples is Lehman brothers bankruptcy - an companies that had lasted for more than 100 years in United States. Hence, it is impossible to buy a stock and didn't monitor it at all because the change nowadays is rapid and unpredictable. A serious investors should always keep an eye on their investments.