Proficiency (noun)

1. The state or quality of being proficient; skill or competence in a particular activity or subject.
2. The level of skill or knowledge that someone has in a particular subject or activity.

Origin:

From old french proficiency, from latin proficientia ("a making progress, proficiency"), from proficientem ("making progress"), present participle of proficere ("to make progress, succeed"), from pro- ("forward") + facere ("to make").

Examples:

1. He has a high proficiency in mathematics.
2. She showed a great proficiency in playing the piano.
3. The student's proficiency in English was very good.
4. The company's proficiency in technology made it stand out in the market.
5. The team's proficiency in teamwork is what helped them win the game.