aptness
Pronunciation:
/ˈæptnəs/noun
Definitions
Suitability; the quality of being apt or suitable
Disposition of the mind; propensity
Example: the aptness of men to follow example
Speed or readiness in learning; docility
Example: An aptness to learn is more observable in some children than in others.
Proneness; tendency
Example: the aptness of iron to rust