Main Entry: boost·er

Pronunciation: \ˈbü-stər\

Function: noun

Date: 1888

: one that boosts: as a : an enthusiastic supporter b : an auxiliary device for increasing force, power, pressure, or effectiveness c slang : shoplifter d : a radio-frequency amplifier for a radio or television receiving set e : the first stage of a multistage rocket providing thrust for the launching and the initial part of the flight f : a substance that increases the effectiveness of a medicament; especially : booster shot