1. the quality of being suitable or appropriate for a particular situation
2. natural ability or talent; quickness to learn or understand

Examples

• The aptness of her comment surprised everyone in the meeting.
• His aptness for mathematics became evident in elementary school.
• The teacher praised the aptness of the student’s analogy.
• She questioned the aptness of wearing casual clothes to the formal event.
• The child’s aptness in learning languages impressed her parents.
• The aptness of the metaphor made the complex concept easier to understand.