On older faucets that are leaking at the handle, there is a packing nut under the handle that wears out over time.
To tighten this packing nut, use an adjustable wrench to tighten the packing nut.
Over-tightening can damage the faucet, so be careful.
This tightening of the nut also affects the handle being able to turn.
As you tighten the nut, feel the handle’s ability to turn.
Balance the turning of the handle with the tightening of the packing nut to stop the leaking water.
If the leak continues, you may have to replace the packing.
Or there may be issues with the stem or other internal components.
If so, the entire faucet may need to be replaced.