精通 (jīngtōng) is a verb meaning 'to master thoroughly' or 'to have expert-level command of' a skill, subject, or language. It combines 精 (jīng), meaning 'refined', 'essence', or 'expert', and 通 (tōng), meaning 'to understand fully', 'to be proficient in', or 'to have comprehensive knowledge'. Together, they convey deep, systematic mastery—not just familiarity or basic competence, but fluency and authoritative understanding.

This word is commonly used in formal or professional contexts: describing expertise in fields like programming, music, medicine, or languages. It often appears with the structure '精通 + [noun]', and typically requires an object—e.g., 精通英语 (master English), 精通钢琴 (master piano playing). Unlike casual terms like 会 (huì, 'can do') or 擅长 (shàncháng, 'be good at'), 精通 implies long-term study, practice, and recognized proficiency.