Fast
Fast adverb - To a full extent or degree.
Usage example: everyone in camp was fast asleep within minutes of hitting the sack
Substantially and fast are semantically related. In some cases you can use "Substantially" instead an adverb "Fast".
Substantially
Substantially adverb - For the most part.
Fast and substantially are semantically related. Sometimes you can use "Fast" instead an adverb "Substantially".
Both words in one sentence
- This is an odd case; Superman really was about as fast as Barry back when those issues were actually written, but Superman was powered down substantially in 1986.
Source: Worf Had the Flu -
They are substantially smarter than trolls, living in villages, making stone tools and weapons and breeding livestock and are very fast and nearly as large (about eight feet tall compared to trolls ten).
Source: Our Ghouls Are Creepier
Cite this Source
Substantially and Fast. (2016). Retrieved 2026, July 21, from https://thesaurus.plus/related/fast/substantially
Fast & Substantially. N.p., 2016. Web. 21 Jul. 2026. <https://thesaurus.plus/related/fast/substantially>.
Substantially or Fast. 2016. Accessed July 21, 2026. https://thesaurus.plus/related/fast/substantially.
Google Ngram Viewer shows how "fast" and "substantially" have occurred on timeline