booster
[noun]
Synonyms: decoy, blind, bonnet, capper, shill, shillaber, stick

[TahlilGaran] English Synonym Dictionary ▲

boost‧er /ˈbuːstə $ -ər/ noun [countable]

1. a small quantity of a drug that increases the effect of one that was given before, so that someone continues to be protected against a disease:
a booster shot

2. something that helps someone or something to increase or improve, or to be more successful or confident:
a booster pump
a profit booster for the company
morale/confidence booster
Mail from home is a big morale booster for faraway troops.

3. a rocket that is used to provide extra power for a spacecraft to leave the Earth:
a giant booster rocket

4. American English someone who gives a lot of support to a person, organization, or idea:
a dance organized by the school’s booster club

[TahlilGaran] Dictionary of Contemporary English ▲