Definition of booster in English:


Syllabification: boost·er
Pronunciation: /ˈbo͞ostər


  • 1A person or thing that helps increase or promote something, in particular.
    More example sentences
    • Volunteer work, in particular, can be an immense confidence booster.
    • Products containing ephedra are often promoted as energy boosters or aids to controlling weight.
    • It is also high in vitamins, minerals, protein, phytochemicals and chlorophyll, and it may work as a cancer preventative and brain booster.
  • 1.1North American A keen promoter of a person, organization, or cause: [as modifier]: athletic booster clubs
    More example sentences
    • In a country where it is illegal to organize many types of public meetings, fans formed booster clubs and canvassed malls to court prospective voters.
    • In fact, if it weren't for parental involvement as sponsors, coaches, booster club participants, etc. most programs would not even survive.
    • In the early twentieth century, booster organizations that favored particular water projects proliferated.
  • 1.2 [in combination] A source of help or encouragement: job fairs are a great morale booster
  • 1.3 Medicine A dose of an immunizing agent increasing or renewing the effect of an earlier one.
    More example sentences
    • Dr. Robbins said that efforts to increase the efficacy of the vaccines will include studies on the effectiveness of a booster dose of the vaccine given one year later.
    • Young children who have not received all five doses of the vaccine may require a booster dose if exposed to an infected family member.
    • I had a booster vaccination last year, needed every ten years.
  • 1.4The first stage of a rocket or spacecraft, used to give initial acceleration.
    More example sentences
    • The camera will be turned on fifteen minutes prior to launch and will show the orbiter and solid rocket boosters on the launch pad.
    • The ground crews will also be monitoring the performance of the orbiter, solid rocket boosters and ground system while the tank is filled with the ultra-cold liquids.
    • In the first scenario, personal spaceflight will use lower-cost versions of classic boosters and spacecraft.
  • 1.5A device for increasing electrical voltage or signal strength.
    More example sentences
    • Antenna boosters help to strengthen the signal between a cell tower and your phone.
    • A booster circuit uses a source voltage to generate a boosted voltage that is higher than the source voltage.
    • Antenna booster for areas with weak signals are another good choice.
  • 2North American informal A shoplifter.

More definitions of booster

Definition of booster in:

Get more from Oxford Dictionaries

Subscribe to remove ads and access premium resources

Word of the day astrogation
Pronunciation: ˌastrəˈgāSHən
(in science fiction) navigation in outer space