Frequency: The word is one of the 3000 most common words in English.
1.
Something that is extensive covers or includes a large physical area.
...an extensive tour of Latin America...
When built, the palace and its grounds were more extensive than the city itself.
ADJ
• extensively
Mark, however, needs to travel extensively with his varied business interests.
ADV: ADV after v
2.
Something that is extensive covers a wide range of details, ideas, or items.
Developments in South Africa receive extensive coverage in The Sunday Telegraph...
The facilities available are very extensive.
ADJ
• extensively
All these issues have been extensively researched in recent years.
ADV: ADV after v, ADV adj/-ed
3.
If something is extensive, it is very great.
The blast caused extensive damage, shattering the ground-floor windows...
The security forces have extensive powers of search and arrest...
ADJ
• extensively
Hydrogen is used extensively in industry for the production of ammonia.
ADV: ADV after v, ADV -ed