boost|er

boost|er «BOOS tuhr», noun.

1. a person or thing that boosts: »

Figurative. His suggestions offer India a self-starter or booster (Harper's).

2. an accessory generator or other device interposed in series in a circuit for increasing the voltage in an electric circuit.

3. a) any one of various devices for increasing the power or thrust of an engine: »

The heavy first stage of the rocket could consist of four…solid-propellant boosters (Time).

b) Also, booster rocket. a rocket attached under the tail assembly of a missile or spacecraft to assist in its takeoff, or some phase of its flight: »

... Saturn, the multistage space booster planned for large payloads (Wall Street Journal).

4. a radio-frequency amplifier between an antenna and a radio or television receiving set.

5. U.S. Informal, Figurative. an enthusiastic supporter of a person, group, institution, or idea.

6. Informal. = booster shot. (Cf. ↑booster shot)

7. U.S. Slang. a thief or shoplifter: »

Male boosters shove suits inside their trench coats while an accomplice distracts the salesman's eye (Harper's).