shift means: Basic dress that is simple and straight. It does not hug the body. Popular in 1960s, and other times when loose fitting styles were popular. In 1960s fashion, a diagonal dart ran from the bustline to the side seam. A sheath, on the other hand, is a straight and fitted, simple dress with vertical darts, bust darts and shaping from sides seams. (in Fashion Dictionary)

What else does shift mean?

Exchange one thing for another in the same category. (in Merlin Dictionary)

Transfer from one location to another. (in Merlin Dictionary)

To change (position, place). (in Merlin Dictionary)

Change (gears), like in an auto. (in Merlin Dictionary)

Phonetically alter as part of systematic historical change (in Merlin Dictionary)

To move in a different direction or place. (in Merlin Dictionary)

You can help others by being there for them. (in Merlin Dictionary)

You can use evasive or tricky methods to get along. (in Merlin Dictionary)

You can change the gears like when you drive an automobile. (in Merlin Dictionary)

Modifications that are part of systematic historical changes. Use of speech sounds. (in Merlin Dictionary)

Substitution is a change in one’s person, or from one configuration to the other. (in Merlin Dictionary)

A team of people who relieve one another regularly. (in Merlin Dictionary)