A tendency or likeliness. Normally used by elitest douche bags when they are trying to assert and display their superior intellect.
"I know your propensity for acting like a total douche bag."
by Leoness8178 June 21, 2007
The statiscal probability of having sex in a given situaltion.
Attending Reed College will increase my propensity to get laid, while attending The Citadel will decrease said propenisty.
by maninboulder August 1, 2009
*noun*; in Keynesian economics, the rate at which aggregate consumption rises in response to a rise in national income.

For example, suppose the marginal propensity to consume (MPC) is 0.95. If the national income is 100 billion dollars, and it rises 10%, then consumption will rise by 9.5 billion, and saving will rise by 0.5 billion.

If this theory is correct, then an expanding economy will suffer insufficient demand for its own output, and a recession will be inevitable.

This is why national governments respond to recessions with deficit spending: they are trying to counteract the MPC's effect on aggregate demand, and bring it in line with potential output.
Not only is the marginal propensity to consume weaker in a wealthy community, but, owing to its accumulation of capital being already larger, the opportunities for further investment are less attractive...

J.M. Keynes, *The General Theory of Employment, Interest, and Money* (1936), Ch.3
by Abu Yahya March 3, 2009
The Asian Propensity to Cluster (APC) refers to the tendency for people of Asian descent to gather in large groups. This is particularly true for Asians experiencing a move to a new social setting, such as college or high school.
Yeah, the Asian Propensity to Cluster is always in full effect at freshman orientation.
by shakeybob December 15, 2010
The natural inclination of certain members of the female gender to have sex with terrible dudes.
Although there are a lot of hot birds in this bar, the Propensity to Bang Douchebags (PBD) is through the roof. We need to skate out of here immediately.
by The Real Matty Dubs August 5, 2008