sag

中文： 下垂、凹陷

1. The state of sinking or bending; a droop. (countable, uncountable)
2. A depression or dip in anything. (countable, uncountable)
3. A place where the surface of the earth, a mountain range, a ridge, etc., sinks or droops. (countable, uncountable)
4. The difference in elevation of a wire, cable, chain or rope suspended between two consecutive points. (countable, uncountable)
5. The difference in height or depth between the vertex and the rim of a curved surface, specifically used for optical elements such as a mirror or lens. (countable, uncountable)
6. A region or spot where the skin has lost some of its elasticity and droops or hangs down. (countable, uncountable)
7. A person with sagging skin. (countable, uncountable)

复数 sags