hydropneumatic
Adjective
Meaning
Pertaining to, or depending upon, both liquid and gaseous substances; as, hydropneumatic apparatus for collecting gases over water or other liquids.
Source: Webster's dictionarySynonyms
Examples
Engineering constraints The Indian Arjun MBT 's hydropneumatic suspension at work, while moving over a bump track.
Gordon Murray devised a " hydropneumatic suspension " system for the BT49C, which allowed the car to settle to a much lower ride height at speed.