Mostly and Substantially

Mostly

Mostly adverb - For the most part.
Usage example: the weather this month has been mostly mild

Substantially is a synonym for mostly in mainly topic. In some cases you can use "Substantially" instead an adverb "Mostly", when it comes to topics like primarily.

Nearby Word: most

Substantially

Substantially adverb - For the most part.
Usage example: the Little House books are substantially based on the memories of Laura Ingalls Wilder

Mostly is a synonym for substantially in primarily topic. You can use "Mostly" instead an adverb "Substantially", if it concerns topics such as mainly.

Both words in one sentence

  • Kinetic Weapons Are Just Better Even after humanity upgrades its tech substantially after the end of the Covenant War, their military still mostly uses conventional ballistic weapons.
  • That said, Senators are still mostly men, and although the constitutional minimum age for Senators is 30, the youngest Senator is typically in his/her late 30s or early 40s, with the vast majority being substantially older.
Cite this Source
Substantially and Mostly. (2016). Retrieved 2026, July 21, from https://thesaurus.plus/related/mostly/substantially
Mostly & Substantially. N.p., 2016. Web. 21 Jul. 2026. <https://thesaurus.plus/related/mostly/substantially>.
Substantially or Mostly. 2016. Accessed July 21, 2026. https://thesaurus.plus/related/mostly/substantially.
Google Ngram Viewer shows how "mostly" and "substantially" have occurred on timeline