BOOSTER

[noun] [C]Certainly, a successful end to the war will be a confidence booster.Seeing the poor performance of their opponents the previous day was a great morale booster to the young team.The two rocket boosters attached to the shuttle's belly drop back to sea and are reused.A booster seat is a removable extra seat put onto a car seat for a child to sit on in order to make the child high enough for the seat belt to fit safely.