extensively

From extensive +‎ -ly.

(Received Pronunciation, Canada) IPA^(key): /ɪkˈstɛn.sɪv.li/
(General American) IPA^(key): /ɪkˈstɛn.sɪv.li/, (rare, maybe erroneous) /ɛkˈstɛn.sɪv.li/
- Audio (Maryland): (file)
(General Australian) IPA^(key): /ɪkˈsten.sɪv.li/
(New Zealand) IPA^(key): /əkˈsten.səv.li/

extensively (comparative more extensively, superlative most extensively)

In an extensive manner, widely.
He has read and traveled extensively.
To a great extent.
He became more extensively involved than he intended.
- 2018 August 18, Michael S. Schmidt and Maggie Haberman, “White House Counsel, Don McGahn, Has Cooperated Extensively in Mueller Inquiry”, in The New York Times‎:
  The White House counsel, Donald F. McGahn II, has cooperated extensively in the special counsel investigation, sharing detailed accounts about the episodes at the heart of the inquiry into whether President Trump obstructed justice, […]

in an extensive manner; having great range; having wide breadth and depth

to a great extent

English