What is the meaning of Felting?

present participle and gerund of felt

The production of felt from wool.

The tangling of woolen fibres (such as when an article of clothing is washed at too high a temperature)

The hobby of making objects, such as soft toys, from felt.

Felt or similar material, usually impregnated with a water-resistant material, or the application of such material, usually to a roof.

Source: wiktionary.org