NOTES ON SURNAMES (HULL) 66
Tharratt – found mainly in Yorkshire at the census of 1891. Tharratts are recorded in Howden, East Yorkshire, in1808; in Sutton on Hull, 1809; In Hull, 1814.
The International Genealogical Index (Latter Day Saints) has earlier parish register extracts, but I am not sure of the reliability of some of them. For instance, there is a baptism at Immingham, North Lincolnshire, in 1591 listed, but other sources suggest that the Immingham parish registers only begin in 1615. Another baptism is alleged to have taken place at Calcethorpe, a deserted village with an abandoned church, in 1635. As a result I am reluctant to take seventeenth and eighteenth century Lincolnshire notices of Tharratts at face value. Perhaps I’m being overly cautious.
As to the meaning of the name I could only see a possible variant of the more common Thorold, a male given name whose first component is Thor, the name of the Germanic god.
Later, a search online turned up the suggestion that the name might be French in origin.
Though I doubted this I looked at possible French origins, and found the names Tharaud and Tharaut. These names are said by one source to be from a word meaning “hillock” or “knoll”; by another source to be from a word, taraud meaning a tap or type of drill. This would have been a metonymic for someone who used such a tool in their work.
That being said, I am still not convinced of a French origin.