definition of
propensity

[1] #1 propensity n. [leaning, tendency] an inclination to do something; "he felt leanings toward frivolity". wn

[2] #2 propensity n. [proclivity, leaning] a natural inclination; "he has a proclivity for exaggeration". wn

[3] #3 propensity n. [aptness] a disposition to behave in a certain way; "the aptness of iron to rust"; "the propensity of disease to spread". wn