In the past, people looked at weather and related it to something in their lives. For instance, cloud types are often described by their shapes in the sky. The mareâs tails are wispy cirrus clouds while the mackerel scales are small clumpy altocumulus clouds resembling fish scales in the sky. In the days of large sailing ships, this meant a storm would be approaching soon and the sails should be lowered to protect from the accompanying high winds.
For me, the best way to remember the difference is that a shift dress actually shifts - with the bottom having a wider skirt than the top; meanwhile, a sheath dress is narrower, with pretty much identical measurements at the bust and the knees. Here is a visual tool to help illustrate the difference:
Dress, costume, gown refer to garments for women. Dress is the general term for a garment: a black dress. Costume is used of the style of dress appropriate to some occasion, purpose, period, or character, especially as used on the stage, at balls, at court, or the like, and may apply to men's garments as well: an 18th-century costume.