Answer:
The share of each additional dollar of income earned that is devoted to saving rather than consumption.
Explanation:
The marginal propensity to save is defined as the fraction of increased income that is reserved for saving and not consumption, and it is the slope of the graph of income against savings.
For example if an individual earns an extra dollar and he has propensity to save of 0.5 that means out of the one dollar he will save 50 cents and spend the remaining 50 cents.