lower
To move something down or make it less.
To lower something means to move it down or make it less. When you lower a flag, you pull it down the pole. When you lower your voice, you speak more quietly. When a store lowers its prices, it reduces what things cost.
The word works in physical ways and abstract ones. You can lower a window shade, lower yourself into a swimming pool, or lower a bucket into a well. But you can also lower your expectations when something seems less likely to happen, or lower your standards when you accept less quality than you normally would.
Sometimes lowering something is practical and helpful: lowering the volume when music gets too loud, or lowering your center of gravity in basketball to stay balanced. Other times it carries a sense of disappointment or compromise, like when someone lowers themselves by insulting others instead of staying dignified.
The opposite of lower is raise or elevate. Think of it this way: if you raise your hand to answer a question, you're lifting it up. If you lower your hand, you're bringing it back down.