An aptitude is a natural ability or talent that someone has.
When people talk about aptitudes, they often mean it's something you have a knack for - maybe playing music, speaking another language, or solving puzzles quickly. Aptitudes can be things you're naturally good at doing from an early age, like being able to draw well without any lessons. They can also develop over time with practice and study, such as becoming proficient in math or learning to play a musical instrument.
Note that "apt" means suitable or fitting, which is related but not exactly the same as having an aptitude for something.
Natural ability to acquire knowledge or skill.
Example: She showed an early aptitude for mathematics.
