延缓 (yán huǎn) means 'to delay, postpone, or slow down' — it often refers to slowing a process or prolonging something that is already underway (e.g., aging, speed). Unlike 推迟 (tuī chí) and 延期 (yán qī), which focus on rescheduling events to a later time, 延缓 emphasizes reducing the speed or rate of something. It is also distinct from 拖延 (tuō yán), which carries a negative sense of procrastination or stalling.