What is another word for choo-choo?
Pronunciation: [t͡ʃˈuːt͡ʃˈuː] (IPA) 
The onomatopoeic word "choo-choo" is commonly used to describe the sound of a train whistle. However, there are many synonyms that can be used to express this same sound. Some of these words include "toot-toot," "whistle," "hooter," "blare," "blast," "honk," and "hoot." Each of these words has a slightly different connotation and may be used in different contexts. "Toot-toot" is often used in a more playful or childlike manner, while "blare" and "blast" suggest a louder or more powerful sound. Regardless of which synonym is used, they all convey the familiar sound of a train winding its way down the tracks.
