English Reference
adverb

extensively

adv.
US /ɪkˈstɛnsɪvɫi/ UK /ɛkstˈɛnsɪvli/ ex·ten·sive·ly

  1. 01 B2 Upper Intermediate

    to a great degree or in a way that covers many details.

    to a significant degree; indicating that a subject or task has been dealt with in a comprehensive or thorough manner.

    Simple

    The researchers studied the problem extensively before suggesting a new solution.

    In context

    The legal team researched the case law extensively to ensure that every possible precedent had been accounted for before the trial began.

    Usage

    Typically follows the verb it modifies or appears at the end of the clause.

  2. 02 B2 Upper Intermediate

    covering a very large space or many different places.

    covering a vast physical area or distributed over a wide range of locations.

    Simple

    This type of tree grows extensively throughout the northern part of the country.

    In context

    The invasive species has spread extensively across the wetlands, threatening the survival of several native plants in the region.

Usage extensively discuss · extensively use

These corals can recolonize damaged reefs but may not build reef structures as quickly or as extensively as the corals that dominated in the past.

Phys.org· 18 Aug 2026

LCDM has become one of the most thoroughly studied and extensively tested theories in ALL of science.

ScienceDaily· 18 Aug 2026

From extensive + -ly.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Level B2 · Upper Intermediate
Frequency Frequent
Updated