water rocket
noun/ˈwɔːtə(ɹ)ˌɹɒkɪt/
Etymology From water + rocket.
1
A rocket that uses water as a propellant, which is forced out of the rocket by compressed air or other gas.
- We built a water rocket in science class today.
Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — list of authors.