Fluid and Permanent

Fluid

Fluid adjective - Likely to change frequently, suddenly, or unexpectedly.
Usage example: his arrival plans are fluid, so expect him anytime

Permanent is an antonym for fluid.

Nearby Word: fluidity

Permanent

Permanent adjective - Lasting forever.

Fluid is an antonym for permanent.

Cite this Source
Permanent and Fluid. (2016). Retrieved 2026, August 10, from https://thesaurus.plus/related/fluid/permanent
Fluid & Permanent. N.p., 2016. Web. 10 Aug. 2026. <https://thesaurus.plus/related/fluid/permanent>.
Permanent or Fluid. 2016. Accessed August 10, 2026. https://thesaurus.plus/related/fluid/permanent.
Google Ngram Viewer shows how "fluid" and "permanent" have occurred on timeline