Profound (adjective)

1. Extremely deep or intense.
2. Of great knowledge or understanding.
3. Characterized by a deep understanding of a subject or insight into its nature.

Origin:

From latin profundus ("deep"), from pro- ("forward") + fundus ("bottom, depth").

Examples:

1. He had a profound understanding of the subject.
2. The book contains profound thoughts on the meaning of life.
3. The impact of the loss was profound and affected her deeply.
4. The musician's work is profound and has a lasting impact on the industry.
5. Her love for him was profound and unshakable.