# STD

CEFR B2 · Noun

Source: https://englishreference.com/word/std
Updated: 2026-10-01

## Definition

Stands for sexually transmitted disease. An infection that people get by having sex with someone who already has it.

For teachers: Abbreviation for sexually transmitted disease. An infection or disease passed from one person to another through sexual contact. Often used interchangeably with STI (sexually transmitted infection) in modern medical contexts.

## Examples

- You should get tested for an STD if you have a new partner.
- Health clinics provide free screenings and advice on how to prevent the spread of an STD.
- Public health initiatives focus on reducing the stigma surrounding an STD to encourage more people to seek early diagnosis and treatment.

## Pitfalls

- Not "a STD" but "an STD" — Use 'an' before acronyms that begin with a vowel sound, such as 'S' (ess).

## Usage notes

- Typically used with the indefinite article 'an' because the first letter is pronounced as a vowel ('ess').

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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.