What does FIELD mean?

noun

1. a piece of land cleared of trees and usually enclosed“he planted a field of wheat”
2. a region where a battle is being (or has been) fought“they made a tour of Civil War battlefields”
3. somewhere (away from a studio or office or library or laboratory) where practical work is done or data is collected“anthropologists do much of their work in the field”
4. a branch of knowledge“in what discipline is his doctorate?”
5. the space around a radiating body within which its electromagnetic oscillations can exert force on another similar body not in contact with it
6. a particular kind of commercial enterprise“they are outstanding in their field”
7. a particular environment or walk of life“his social sphere is limited”
8. a piece of land prepared for playing a game“the home crowd cheered when Princeton took the field”