[ suh-stey-ner ]
/ səˈsteɪ nər /


a person or thing that sustains.
  1. any stage of a multistage rocket or guided missile that sustains flight after the burnout of the booster.
  2. the rocket engine or cluster of engines contained in such a stage.

Origin of sustainer

First recorded in 1350–1400, sustainer is from the Middle English word sosteynere. See sustain, -er1 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for sustainer

British Dictionary definitions for sustainer

/ (səˈsteɪnə) /


a rocket engine that maintains the velocity of a space vehicle after the booster has been jettisoned
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012