an ability that has been acquired by training
"She spent years practicing to develop her skill in playing the violin."
Capacity to do something well; technique, ability. Skills are usually acquired or learned, as opposed to abilities, which are often thought of as innate.
"After months of practice, the young pianist finally demonstrated enough skill to perform a concerto without missing a note."
In plain English: A skill is something you can do well because you have practiced it enough times to get good at it.
"She worked hard to improve her cooking skill."
Usage: Use skills when referring to specific techniques that can be learned and improved through practice, such as coding or playing an instrument. Avoid using it for innate talents like a natural sense of rhythm, which is better described as an ability.
To set apart; separate.
"The chef used a sharp knife to skillfully slice the tomato into perfect wedges."
In plain English: To skill something is to make it more skilled, though this usage is rare and people usually just say they are improving at something instead.
"The apprentice skillfully carved the intricate details into the wooden statue."
Great, excellent.
"The chef's skill at plating made every dish look like a work of art."
"She is a skill manager who knows exactly how to handle her team."
The word skill comes from Old Norse skil, which originally meant "a distinction" or "discernment." It entered English via Middle English, carrying with it the sense of knowing how to separate or judge differences.