专心 (zhuānxīn) literally combines 专 (zhuān), meaning 'exclusive' or 'focused', and 心 (xīn), meaning 'heart' or 'mind'. Together, they form a verb meaning 'to concentrate' or 'to focus one's attention fully on something'. It emphasizes mental engagement without distraction — not just physical presence, but active, undivided attention. The word is commonly used in academic, work, and daily life contexts to describe intentional focus.

Although it functions primarily as a verb, 专心 can also appear as an adjective before a noun (e.g., 专心的学习 — 'concentrated study') or as an adverbial phrase after a subject (e.g., 他专心看书 — 'He reads with full concentration'). It carries a positive, commendable connotation — implying discipline, diligence, and self-control. Unlike casual terms like 注意 (zhùyì, 'to pay attention'), 专心 implies deeper, sustained mental involvement.