# unintelligible

/ˌənɪnˈtɛɫədʒəbəɫ/ (US) · /ˌʌnɪntˈɛlɪdʒəbəl/ (UK) · CEFR B2 · Adjective

Source: https://englishreference.com/word/unintelligible
Updated: 2026-05-25

## Definition

impossible to understand because the speech or writing is not clear. You use this when someone is mumbling or the handwriting is very messy.

For teachers: impossible to understand or comprehend, typically due to poor articulation, low audio quality, or illegible script. Often used predicatively after linking verbs like 'be', 'become', or 'sound'.

## Examples

- His handwriting is so messy that it is almost unintelligible.
- The recording was so old and scratchy that most of the interview remained unintelligible to the researchers.
- While the technical jargon was familiar to the engineers, the dense mathematical proofs in the appendix were largely unintelligible to the lay audience attending the lecture.

## Pitfalls

- Not "The book was unintelligible to read." but "The book was unintelligible." — Unintelligible describes the quality of the communication itself; adding 'to read' is redundant and grammatically awkward.

## Usage notes

- Often follows a linking verb or modifies nouns related to communication like 'speech', 'writing', or 'sounds'.

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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.