From late Middle English, borrowed from Late Latin extensīvus, from Latin extensus.

• IPA: /ɪkˈstɛn.sɪv/
• (America) IPA: /ɛksˈtɛn.sɪv/

extensive

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.
   • 1650, Thomas Browne, Pseudodoxia Epidemica: […], 2nd edition, London: […] A[braham] Miller, for Edw[ard] Dod and Nath[aniel] Ekins, […], →OCLC ↗:

     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.

4. (physics) Having a combined system entropy that equals the sum of the entropies of the independent systems.

• extend
• extense
• extent

• French: étendu
• German: umfangreich
• Italian: vasto, molto, estenso, esteso, grande, ricco
• Portuguese: extensivo
• Russian: обши́рный
• Spanish: extenso