posigrade rocket

[poz-i-greyd]

noun Rocketry.

an auxiliary rocket used to separate the sections of a multistage rocket, fired in the direction of flight.

Origin of posigrade rocket

1960–65; posi(tive) + -grade (perhaps modeled on retrograde)

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018