Cowan is not a word we encounter much nowadays. It originated back in the days of mediaeval stonemasons. Building in stone required training and long and patient study, to understand how a building’s structure and stability depended on geometry. This understanding was known as a ‘secret art and hidden mystery’, not to be shared by the stonemasons with their untrained and unskilled fellow workers, known as cowans.
The word was also used to refer to dry stone wallers, who built walls by piling up field stones, a technique that is still used today in many parts of the UK. These workers did not use mortar and shaped stones (‘ashlars’) that were used by stonemasons to build churches, castles and cathedrals. Hence, among stonemasons, a cowan was an outsider who must be kept at a distance.
In Scotland, the word was used to refer to stonemasons who had never completed their apprenticeships, but who worked alongside qualified stonemasons. They were the ‘cowboy builders’ of their time.