A more thorough explanation:

Definition: A dowager-queen is the widow of the king of England. She is also known as a queen dowager. She enjoys most of the privileges of a queen consort, but it is not considered high treason to conspire against her or violate her chastity because the succession to the crown is not endangered. However, no man can marry a queen dowager without special permission from the king, or they risk losing their lands and goods. If a queen dowager marries a subject, she does not lose her regal dignity, unlike peeresses dowager who lose their peerage when they marry commoners.

Example: Queen Elizabeth, the Queen Mother, was a dowager-queen after the death of her husband, King George VI. She continued to carry out royal duties and was highly respected by the public.

Explanation: Queen Elizabeth, the Queen Mother, was the widow of King George VI, and as such, she was a dowager-queen. She enjoyed most of the privileges of a queen consort, such as being addressed as "Your Majesty" and having a royal household. She continued to carry out royal duties and was highly respected by the public, even though she was no longer the queen consort.