unmastered
/(ˌ)ʌnˈmɑːstəd/ /(ˌ)ʌnˈmastəd/adjective
Not mastered; uncontrolled, unrestrained; (of a skill, ability, etc.) in which one has yet to gain full proficiency.
Origin
Mid 16th century; earliest use found in Thomas Norton (d. 1584), lawyer and writer. From un- + master + -ed.