Sub-standard
Unsound and sub-standard are semantically related. In some cases you can use "Unsound" instead an adjective phrase "Sub-standard".
Unsound
Unsound adjective - Having or showing a very abnormal or sick state of mind.
Sub-standard and unsound are semantically related. Sometimes you can replace phrase "Sub-standard" with "Unsound", this terms are similar.
Cite this Source
Unsound and Sub-standard. (2016). Retrieved 2026, August 09, from https://thesaurus.plus/related/sub-standard/unsound
Sub-standard & Unsound. N.p., 2016. Web. 09 Aug. 2026. <https://thesaurus.plus/related/sub-standard/unsound>.
Unsound or Sub-standard. 2016. Accessed August 09, 2026. https://thesaurus.plus/related/sub-standard/unsound.