Definition of "extensive"

extensive

/ɪkˈstɛn.sɪv/

adjective
comparative more extensive, superlative most extensive
1. Having a great extent; covering a large area; vast.
  Quotations
  In the second century of the Christian era, the Empire of Rome comprehended the fairest part of the earth, and the most civilised portion of mankind. The frontiers of that extensive monarchy were guarded by ancient renown and disciplined valour.
  1776, Edward Gibbon, chapter 1, in The History of the Decline and Fall of the Roman Empire
2. (figurative) Considerable in amount.
3. Serving to extend or lengthen; characterized by extension.
  Quotations
  For station is properly no rest, but one kind of motion, relating unto that which physicians (from Galen) do name extensive or tonical; that is, an extension of the muscles and organs of motion, maintaining the body at length, or in its proper figure.
  1650, Thomas Browne, Pseudodoxia Epidemica: […], 2nd edition, London: […] A[braham] Miller, for Edw[ard] Dod and Nath[aniel] Ekins, […]
4. (physics) Having a combined system entropy that equals the sum of the entropies of the independent systems.
  Quotations
  According to Tsallis (1988), the entropy was extensive for T = 1, superextensive for t < 1 and subextensive for t > 1.
  2000, Roman Teisseyre, Eugeniusz Majewski, Earthquake Thermodynamics and Phase Transformation in the Earth's Interior