# Choo

/ˈtʃu/ (US) · CEFR A1 · Interjection

Source: https://englishreference.com/word/choo
Updated: 2026-08-15

## Definition

the sound people make to imitate a steam train. You might say this when playing with children or talking about old engines.

For teachers: an onomatopoeic representation of the sound produced by a steam locomotive. Frequently doubled as 'choo-choo' in child-directed speech.

## Examples

- The little boy pointed at the train and said choo.
- The children lined up behind their teacher and made a loud 'choo' sound as they pretended to be a train.
- While modern electric trains hum quietly, the classic steam engine is still immortalized in children's literature by the rhythmic 'choo' of its exhaust.

## Usage notes

- Often used as a reduplicated form ('choo-choo') which can function as a nursery noun for a train.

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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.