What is the meaning of phrase hit upon a scheme?

The phrase "hit upon a scheme" means to suddenly think of or discover a plan or idea, often unexpectedly. It implies that the idea came to the person in a flash of insight, like a light bulb switching on.

Here are some synonyms for "hit upon":

* Stumble upon

* Chance upon

* Discover

* Invent

* Conceive of

Here are some examples of how the phrase is used:

* "After days of struggling, she finally hit upon a scheme to get the money she needed."

* "He hit upon a scheme to make a quick buck by selling used books online."

* "The detective hit upon a scheme to catch the thief red-handed."

The word "scheme" implies a plan that is often clever, perhaps even a bit underhanded or manipulative. However, it's important to note that the term can have neutral connotations as well.