# undesirable

/ˌəndɪˈzaɪɹəbəɫ/ (US) · /ˌʌndɪzˈaɪəɹəbəl/ (UK)

Source: https://englishreference.com/word/undesirable
Updated: 2026-08-08

## Senses

### 1. not wanted or unpleasant

adjective · CEFR B2

describing something that you do not want to happen because it is bad or causes problems.

For teachers: not desirable or pleasing; describing an outcome or quality that is objectionable or disadvantageous.

- The new factory might have some undesirable effects on the local environment.
- The medication was effective at treating the primary infection, though it produced several undesirable side effects that patients found difficult to tolerate.

### 2. an unwanted person

noun · CEFR C1 · Formal

a person who is not wanted in a place because they are seen as trouble or low-quality.

For teachers: a person considered socially or morally objectionable. Often used in the plural to refer to a group of people perceived as a threat to order.

- The hotel security tried to keep undesirables away from the private party.
- The local council was criticized for its attempts to clear the park of what it termed 'undesirables' during the international summit.

Usage: Usually appears in the plural form 'undesirables'.

Teaching tip: This noun sense can sound quite harsh or judgmental; it is often used by authorities or in older literature to describe people they want to remove.

## Examples

- The medicine has some undesirable side effects.
- The new factory might bring jobs, but the increased traffic is an undesirable consequence for the local residents.
- While the policy was designed to stimulate growth, it inadvertently created several undesirable market conditions that the central bank struggled to correct over the following fiscal year.

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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.