booster rocket
Noun
Meaning
the first stage of a multistage rocket
Source: WordNetSynonyms
Hypernyms
Examples
An O-ring seal in the right booster rocket failed at liftoff, leading to subsequent structural failures.
The unmanned craft was lifted into orbit by the specially designed Energia booster rocket.
Large pieces of the plutonium contaminated missile including pieces of the warhead, booster rocket, engine, re-entry vehicle and missile parts fell back on Johnston Island.