Noah Webster
Proclivity
PROCLIV'ITY, noun [Latin proclivitas, proclivis; pro and clivus, a cliff.]
1. Inclination; propensity; proneness; tendency.
The sensitive appetite may engender a proclivity to steal, but not a necessity to steal.
2. Readiness; facility of learning.
He had such a dexterous proclivity that his teachers were fain to restrain his forwardness.