extensive

adjective4

1. •
   Having a great extent; covering a large area; vast.
2. •
   (figurative) Considerable in amount.

   • I have done extensive research on the subject.
3. •
   Serving to extend or lengthen; characterized by extension.
4. •
   Having a combined system entropy that equals the sum of the entropies of the independent systems.

   • According to Tsallis (1988), the entropy was extensive for T = 1, superextensive for t < 1 and subextensive for t > 1. — 2000