Fast and Perfidious
Opposite meaning words
Fast
Fast adjective - Firm in one's allegiance to someone or something.
Usage example: the two girls soon became fast and inseparable friends
Perfidious is an antonym for fast.
Perfidious
Perfidious adjective - Not true in one's allegiance to someone or something.
Usage example: a perfidious campaign worker revealed the senator's strategy to his leading rival for the nomination
Fast is an antonym for perfidious.
Nearby Words: perfidy, perfidiously
Cite this Source
Perfidious and Fast. (2016). Retrieved 2026, August 15, from https://thesaurus.plus/related/fast/perfidious
Fast & Perfidious. N.p., 2016. Web. 15 Aug. 2026. <https://thesaurus.plus/related/fast/perfidious>.
Perfidious or Fast. 2016. Accessed August 15, 2026. https://thesaurus.plus/related/fast/perfidious.
Google Ngram Viewer shows how "fast" and "perfidious" have occurred on timeline