extensively

American  

[ik-sten-siv-lee] / ɪkˈstɛn sɪv li /

adverb

1. so as to cover a wide range or area; broadly.

   He reads and travels extensively and is regarded as one of the best-informed men anywhere.

2. in a far-reaching, comprehensive way; thoroughly.

   All the science departments have been extensively renovated, with new tutorial rooms and well-equipped laboratories.

3. at great length or in great detail.

   He spoke extensively about the threats his daughter faces as a transgender individual.

4. to a great degree or in great amounts or numbers; a lot.

   Although the river is used extensively by boaters, no official map has been developed to show the best places to dock, things to see, and hazards to avoid.

---

Other Word Forms

• nonextensively adverb
• preextensively adverb

Etymology

Origin of extensively

extensive ( def. ) + -ly

Example Sentences

Inflammatory bowel disease, which includes ulcerative colitis and Crohn's disease, has not been studied extensively when it comes to diet.

From Science Daily • Apr. 3, 2026

Apart from bottled water and beverages, PET packaging is also used extensively in industries like beauty, pharmaceuticals and even in restaurants and food delivery as customers seek out convenience and affordability.

From BBC • Apr. 2, 2026

Even though I research extensively and pride myself on accuracy, without direct experience things go wrong.

From Slate • Mar. 28, 2026

Traveling extensively with her archaeologist husband in Mesopotamia, Christie was adamant that “all I needed was a steady table and a typewriter.”

From The Wall Street Journal • Mar. 27, 2026

Leah’s book does extensively and for the most part accurately quote actual letters and newspaper clippings.

From "American Spirits" by Barb Rosenstock

Related Words

• broadly
• largely