Difference between Overflow and Overspill

Overflow

Part of speech: noun

Definition: The spillage resultant from overflow; excess.

Part of speech: verb

Definition: To fill beyond the limits of a container or system. To compute a number outside the range of (a register or variable which is holding it).

Example sentence: When the heart is full, the eyes overflow.

Overspill

Part of speech: noun

Definition: That which spills over.