Key
Key adjective - Coming before all others in importance.
Vast
Vast adjective - Unusually large.
Mutual synonyms
Both words in one sentence
-
The vast majority of companies still have no backup plan for when their key server or servers go down.
Source: Master Computer - Even if all I witnessed was jaywalking, it's probably key to a vast mystery involving arson and murder that the perp won't hesitate to kill over.
-
Daring Do and the Army of None: Daring has heard of an ancient legend concerning a sorcerer's amulet that is the key to commanding a vast and deadly legion of phantoms - the Army of None.
Source: Just For Fun / Daring Do
Cite this Source
Vast and Key. (2016). Retrieved 2026, August 03, from https://thesaurus.plus/related/key/vast
Key & Vast. N.p., 2016. Web. 03 Aug. 2026. <https://thesaurus.plus/related/key/vast>.
Vast or Key. 2016. Accessed August 03, 2026. https://thesaurus.plus/related/key/vast.
Google Ngram Viewer shows how "key" and "vast" have occurred on timeline