The old kettle began skumming, spewing tiny bubbles over the rim.

After the storm, the river skums, leaving a layer of foam and debris along the banks.

He skummed the milk before setting it aside to make cheese.

After the long voyage, the ship's bilge was covered in a gray skum that told of the salt and soot it had gathered.

Please skum the broth before serving so the soup remains clear.