# vastly

/ˈvæstɫi/ (US) · /vˈɑːstli/ (UK) · CEFR B2 · Adverb

Source: https://englishreference.com/word/vastly
Updated: 2026-05-03

## Definition

to a very great degree. You use this when you want to emphasize that a difference or change is very large.

For teachers: to a very great extent or degree; immensely. Frequently modifies adjectives or verbs to emphasize a significant disparity or improvement.

## Examples

- The new model is vastly better than the old one.
- The quality of life in the city has improved vastly since the new public transport system was built.
- While the two theories share a common origin, their modern applications have diverged vastly, leading to entirely different conclusions in the field of quantum mechanics.

## Pitfalls

- Not "The population is vastly." but "The population is vast." — Learners sometimes use the adverb 'vastly' when the sentence requires the adjective 'vast' to describe a noun.

## Usage notes

- Typically placed before the adjective it modifies or after the verb it emphasizes.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.