extensively [ɪksˈtensɪvlɪ] ADV
1. (= on a large scale) [work, travel] → mucho; [write, speak] → ampliamente, mucho; [damage] → considerablemente; [restore, modify] → considerablemente, en gran parte
he travelled extensively in Mexico → viajó mucho por México
the story was covered extensively in the papers → la historia tuvo una amplia cobertura en la prensa
these grapes are grown extensively in Bordeaux → estas uvas se cultivan extensamente en Burdeos
2. (= in detail) [discuss, write] → mucho; [study, research, revise] → exhaustivamente, a fondo
I have quoted extensively from the article → he utilizado muchas citas del artículo