Dewart Name Meaning. Scottish: variant of Dewar, formerly found chiefly in Lanarkshire.Possibly an altered spelling of Dutch de Waart, a variant of De Weerd.Possibly a variant spelling of German Deward, from an old personal name Teudoard, composed of Old High German diot ‘people’, ‘nation’ + wart- ‘observer’, ‘guard’.lick on a circle in the chart to view Dewart birth and death records. An unusually short lifespan might indicate that your ancestors lived in harsh conditions. A short lifespan might also indicate health problems that were once prevalent in your family. The SSDI is a searchable database of more than 70 million names.