Knowledgeable (adjective)

1. Having a lot of knowledge and information about a particular subject or many subjects.
2. Having practical experience and understanding in a certain field.

Origin:

Derived from the word 'knowledge' which comes from the old english 'cnowledg' and the middle english 'knowledg' meaning 'awareness, understanding'. the word 'knowledgeable' was first used in the late 17th century.

Examples:

1. John is a knowledgeable person about all the different types of cars.
2. She was knowledgeable about the company's financial status, so she was able to help her boss with the budget.
3. The author of the book was knowledgeable about the history of medieval Europe.
4. The doctor was knowledgeable about the latest medical techniques.
5. He was knowledgeable about the different wine types and their origin.