- Engaged in the business of giving expert advice to people working in a professional or technical field.
- The business of giving expert advice to other professionals, typically in financial and business matters.
- Expert skill or knowledge; expertness; know-how: business expertise.
- A written opinion by an expert, as concerning the authenticity or value of a work of art, manuscript, etc.
- The condition or state of knowing a subject or topic with a familiarity that is developed by extensive experience or association.
- The thorough understanding of an art, science, method, or technique.