Noun
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.
Source: Webster's dictionary"This sucks on so many levels." - Dialogue from "Jason X" Rare for a movie to so frankly describe itself. "Jason X" sucks on the levels of storytelling, character development, suspense, special effects, originality, punctuation, neatness and aptness of thought. Roger Ebert
In an aphorism, aptness counts for more than truth. Mason Cooley
the phrase had considerable aptness Source: Internet
the aptness of iron to rust Source: Internet
the propensity of disease to spread Source: Internet
Nay, it is likened to a man; and as we consider feature and composition in a man, so words in language; in the greatness, aptness, sound structure, and harmony of it. Source: Internet