The word skill is a noun. Skill means (1) ability to produce solutions in some problem domain, (2) an ability that has been acquired by training.
The following articles and web pages elaborate on the word skill.
Cake decorating is a highly sought-after culinary skill, and every cake is unique! Cakes can be iced with butter cream, royal, fondant, or cooked icings, and may feature various embellishments as well.
Researchers have found that children who need assistance improving their social skills might benefit more when grouped with peers who have similar social skill levels, rather than with peers who have a similar disability or disorder.
Science Daily. Wednesday, 15 Aug 2018 13:05:31 EDT.