supercritical fluid

https://doi.org/10.1351/goldbook.S06138
The defined state of a compound, mixture or element above its critical pressure (p c) and critical temperature (T c).
Source:
PAC, 1993, 65, 2397. 'Nomenclature for supercritical fluid chromatography and extraction (IUPAC Recommendations 1993)' on page 2399 (https://doi.org/10.1351/pac199365112397)