from
The Collaborative International Dictionary of English v.0.48
Booster \Boost"er\ (b[=oo]st"[~e]r), n.
1. (Elec.) An instrument for regulating the electro-motive
force in an alternating-current circuit; -- so called
because used to "boost", or raise, the pressure in the
circuit.
[Webster 1913 Suppl.]
2. an enthusiastic supporter.
[PJC]
3. the first stage of a multistage rocket, providing all or
part of the driving force at lift-off and until the second
stage ignites, whether or not the booster stage is
detached after the fuel is spent. Also called {booster
rocket}. In some cases, a booster has been used to assist
the takeoff of airplanes.
[PJC]
4. (Med.) an immunizing medication given after an initial
immunizing treatment, to provide increased or extended
immunity. Also called {booster dose}. When in the form of
an injection, it may be called a {booster shot}.
[PJC]
5. any auxiliary device or part of a device to provide
increased power, force, or effectiveness, as with a
pumping device.
[PJC]
6. (Mil.) an explosive charge which is more powerful than a
primer, used in conjunction with a primer to assure
detonation of the main charge. Integrated blasting caps
containing separate compartments for primer and booster
are used as detonators for certain explosives.
[PJC]