noun
skyrocket; bottle rocket
A small firework attached to a stick that shoots into the air, often with a whistling sound. Common in summer festivals and personal use.
子供たちが公園でロケット花火を飛ばしていた。
The children were launching bottle rockets in the park.
ロケット花火は音が大きいので、夜遅くに使わないでください。
Please don't use skyrockets late at night because they are loud.
Compound of ロケット (rocket) and 花火 (fireworks), literally 'rocket fireworks'. The term directly describes the firework's rocket-like propulsion.