Definition of "back pressure" [back pressure]

• See under Pressure. (adjective)
• Pressure which resists the motion of the piston, as the pressure of exhaust steam which does not find free outlet. (noun)

Gnu Collaboartive International Dictionary of English: licensed under The Code Project Open License (CPOL)

• "Eventually the investigators determined that a frozen regulator, a faulty relief valve, and a rapid buildup of back pressure caused the center structure of the X-15’s ammonia tank to ram and smash open the control system’s hydrogen peroxide sphere."