Fast
Fast adjective - Firm in one's allegiance to someone or something.
Usage example: the two girls soon became fast and inseparable friends
Trustworthy and fast are semantically related. In some cases you can use "Trustworthy" instead an adjective "Fast".
Trustworthy
Trustworthy adjective - Worthy of one's trust.
Usage example: a trustworthy bodyguard who would never blab to the tabloids
Fast and trustworthy are semantically related. Sometimes you can use "Fast" instead an adjective "Trustworthy".
Mutual synonyms
Cite this Source
Trustworthy and Fast. (2016). Retrieved 2026, July 29, from https://thesaurus.plus/related/fast/trustworthy
Fast & Trustworthy. N.p., 2016. Web. 29 Jul. 2026. <https://thesaurus.plus/related/fast/trustworthy>.
Trustworthy or Fast. 2016. Accessed July 29, 2026. https://thesaurus.plus/related/fast/trustworthy.
Google Ngram Viewer shows how "fast" and "trustworthy" have occurred on timeline