Flatten
Flatten verb - Become flat or flatter.
Usage example: The landscape flattened
Flatten out is a synonym for flatten. In some cases you can use "Flatten out" instead a verb "Flatten".
Flatten out
Cite this Source
Flatten out and Flatten. (2016). Retrieved 2026, July 21, from https://thesaurus.plus/related/flatten/flatten_out
Flatten & Flatten out. N.p., 2016. Web. 21 Jul. 2026. <https://thesaurus.plus/related/flatten/flatten_out>.
Flatten out or Flatten. 2016. Accessed July 21, 2026. https://thesaurus.plus/related/flatten/flatten_out.
Google Ngram Viewer shows how "flatten" and "flatten out" have occurred on timeline