Definition from Wiktionary, the free dictionary
- Fitness; suitableness; appropriateness; as, the aptness of things to their end.
- Disposition of the mind; propensity; as, the aptness of men to follow example.
- Quickness of apprehension; readiness in learning; docility; as, an aptness to learn is more observable in some children than in others.
- Proneness; tendency; as, the aptness of iron to rust.