What does the idiom spread it on thick mean?

"Spread it on thick" is an idiom meaning to exaggerate or embellish something excessively. It can also be used to describe applying something liberally, often to the point of being excessive.

Here are some examples:

* Exaggeration: "He spread it on thick about how much he earned, but I know he's not making that much."

* Liberal application: "She spread the butter on thick, so much so that it was dripping off the bread."

The idiom often implies that the person is trying to deceive or impress someone else with their story or actions.