# effective

/ˈifɛktɪv/ (US) · /ɪfˈɛktɪv/ (UK)

Source: https://englishreference.com/word/effective
Updated: 2026-06-19

## Senses

### 1. successful in producing a result

adjective · CEFR B1

producing the result that you wanted or intended.

For teachers: successful in producing a desired or intended result. Often used to describe solutions, treatments, or methods.

- The new medicine was very effective at reducing her headache quickly.
- The marketing campaign proved highly effective, resulting in a twenty percent increase in new subscriptions over the first quarter.

Usage: Commonly modifies nouns like 'method', 'solution', 'treatment', or 'way'.

### 2. starting to apply or operate

adjective · CEFR B2 · Formal

starting to be used or starting to be a law.

For teachers: coming into operation or effect; officially in use or valid from a specific time.

- The new tax rules will be effective from the first of January.
- The revised safety regulations become effective immediately, and all site managers must ensure compliance by the end of the business day.

Usage: Often followed by the preposition 'from' when indicating a start date.

### 3. actual or real

adjective · CEFR C1 · Academic

the real or actual situation, even if it is not the official one.

For teachers: existing in fact, though not necessarily intended or officially acknowledged.

- Although he is the assistant, he is the effective leader of the team.
- The effective cost of the loan was much higher than the advertised interest rate once the hidden fees were included.

Teaching tip: In academic contexts, this sense contrasts 'effective' (the reality) with 'nominal' (the name or theory).

### 4. soldiers fit for duty

noun · CEFR C2 · Technical · Formal

a soldier who is healthy and ready to fight.

For teachers: a soldier or member of a military unit who is fit for active service.

- The general counted his effectives before the morning march.
- After the long winter campaign, the regiment's total number of effectives had dropped to less than half of its original strength.

## Examples

- This new medicine is very effective against headaches.
- The marketing team needs to find a more effective way to reach younger customers online.
- While the initial strategy appeared sound, it proved less effective in practice due to unforeseen logistical hurdles and a lack of clear communication between departments.

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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.