The term 'Sphere of Action' refers to a range of activities or areas in which an individual or organization is involved. The crossword solutions for this term are ARENA (5 letters), ORBIT (5 letters) and HOTSPOT (7 letters). An ARENA is a large, enclosed area used for sports or entertainment events. An ORBIT is the path of a celestial body or object around another body due to the gravitational attraction between them. A hotspot is an area of intense activity or interest. Together, these three words represent the various aspects of a sphere of action.