Acumen (noun)

1. The ability to make good judgments and take quick decisions.
2. The ability to understand and think deeply about a subject.

Origin:

Mid 16th century: from latin acumen, from acuere "sharpen".

Examples:

1. He has a great acumen for business.
2. Her acumen for solving complex problems is impressive.
3. The CEO's acumen was key to the success of the company.
4. His acumen in the field of physics is well-known.
5. Her acumen in the field of politics is highly respected.