reverse osmosis unit

reverse osmosis (water) purification unit (ROPU / ROWPU)

shipboard reverse osmosis desalinator (SROD)

reverse bearing

reverse engineering ( back- wards engineering)

reverse gear

reverse one's field

reverse slope

reverse slope defense

reverse transit

ditch in reverse

ditching in reverse

idler reverse gear

worm reverse gear

engaging reverse gear

reverse idle thrust

reverse-flow

reverse-flow combustion chamber

reverse flow

reverse pitch of airscrew

reverse thrust noise

reverse the field

battery coolant unit / battery-coolant unit (BCU)

gear reduction unit / gear-reduction unit

position and navigation unit / position navigation unit (PNU)

pinch (a unit) out of a large unit

adjacent unit

administrative support unit

air assault infantry unit

air defense fire unit

air filtration unit

alarm unit

armored cavalry unit