"Rule of thumb". In Tudor times it was legal for a man to beat his wife with a stick to keep he in line and make her know her place. However, the stick he used could not be thicker than his thumb - hence the rule of thumb.
In Tudor England there was obviously no central heating, so to help keep warmth in and the drafts out, folk would through old straw after threshing onto the floors. However, it was found that when opening doors, the straw (or thresh) would spill out. Some bright spark came up with the idea of placing a piece of wood in the doorway to stop the thresh for falling out. This of course became known as the "thresh hold".
Is this subject of interest and if so does anyone have others?
They could be the meaning of nursery rhymes, names of objects, the lore behind proverbs or just everyday sayings.
I look forward to seeing them.