retro-rocket

noun

ret·​ro-rock·​et ˈre-trō-ˌrä-kət 

: an auxiliary rocket engine (as on a spacecraft) used in decelerating

Word History

First Known Use

1951, in the meaning defined above

Kids Definition

retro-rocket

noun

ret·​ro-rock·​et

ˈre-trō-ˌräk-ət

: a rocket (as on a space vehicle) used to slow forward motion