休闲 (xiūxián) is a verb meaning to relax and actively enjoy leisure time—e.g., taking a walk or hanging out on weekends. It differs from 闲 (xián), an adjective describing a state of being free or not busy, and 空闲 (kòngxián), a noun/adjective for free time or a period with nothing to do. 休闲 is about the purposeful activity; 闲/空闲 describe the available time itself.