Noun
English Wikipedia has an article on:pump-jetWikipedia
pump-jet (plural pump-jets)
(nautical) A marine system that creates a jet of water for propulsion of watercraft.
However, in the novel the Red October did not use MHD, but rather something more similar to the above-mentioned pump-jet. Source: Internet
Toward the end of the 20th century, some submarines—such as the British Vanguard class—began to be fitted with pump-jet propulsors instead of propellers. Source: Internet