To sink or droop below level from weight or age

• To lose firmness or elasticity and become loose
• To decline in energy, morale, or performance

A droop or downward bend

• The vertical dip of a suspended wire or cable
• The depth between the vertex and the rim of a curved surface
• A low spot or depression in a surface or ridge

To idle along or lag, moving slowly and heavily

To make bend or sink by loading or weight

Initialism for Screen Actors Guild, U.S. performers’ union