1. Genuine and authentic mastery or competence in a skill, language, or subject area; the actual ability to perform with competence rather than apparent or superficial knowledge
True proficiency in a language requires years of dedicated study and practice.
Verdadeira proficiência em um idioma requer anos de estudo dedicado e prática.
2. The state of being truly skilled or expert at something, demonstrated through practical application and consistent results
He achieved true proficiency in playing the piano after a decade of lessons.
Ele alcançou verdadeira proficiência em tocar piano após uma década de aulas.