WHAT'S IN A NAME ?
In Dr. Samuel Johnson's "Dictionary Of The English Language" (1756) we find "SMOCK (Saxon) a woman's undergarment - a shift".
Parson Woodforde in the 18th century records in his diary that women raced for a "shift" at the local fair. I have found no mention of men wearing smocks in earlier times.
All mills - including Jack - are feminine, so why dress them in a male garment ?
In future I will say "Smock - after the old English name for a woman's undergarment !"