Building up
Extension and building up are semantically related. In some cases you can use "Extension" instead a noun phrase "Building up".
Extension
Extension noun - The act of making longer.
Building up and extension are semantically related. Sometimes you can use "Building up" instead a noun "Extension".
Cite this Source
Extension and Building up. (2016). Retrieved 2026, August 15, from https://thesaurus.plus/related/building_up/extension
Building up & Extension. N.p., 2016. Web. 15 Aug. 2026. <https://thesaurus.plus/related/building_up/extension>.
Extension or Building up. 2016. Accessed August 15, 2026. https://thesaurus.plus/related/building_up/extension.
Google Ngram Viewer shows how "building up" and "extension" have occurred on timeline