1) French word used in English 2) Impossible to compress 3) Incapable of being compressed 4) Not compressible 5) Resisting compression 
Vehicles built by the Nash Motors corporation. Also includes those cars branded Nash built after the merger with the Hudson Motor Car corporation to form American Motors Corporation. ...
• (a.) Not compressible; incapable of being reduced by force or pressure into a smaller compass or volume; resisting compression; as, many liquids and solids appear to be almost incompressible.
In`com·press'i·ble adjective [ Prefix in- not + compressible : confer French incompressible .] Not compressible; incapable of being reduced by force or pressure into a smaller compass or volume; resisting compression; as, many liquids and solids appear to be almost incompressib...
[adj] - impossible to compress
adjective impossible to compress; resisting compression; `mounds of incompressible garbage`
Incapable of being compressed by pressure and maintaining a relatively fixed volume. Gases are compressible, while liquids are relatively incompressible.
not compressible.