灵敏 (líng mǐn) is an adjective meaning 'keen' or 'sensitive', describing a sharp, responsive ability to detect subtle changes — especially in perception, movement, or reaction. The character 灵 (líng) conveys 'spiritual agility', 'nimbleness', or 'liveliness', while 敏 (mǐn) means 'quick to perceive or respond', often implying mental or physical alertness. Together, they emphasize refined responsiveness: not just fast, but accurate and finely tuned.

This word is frequently used to describe animals’ senses (e.g., a cat’s hearing or a dog’s nose), human sensory acuity (like touch or hearing), or even abstract qualities like 'a sensitive radar system' or 'a keen business instinct'. It carries a positive, appreciative tone and is common in scientific, descriptive, and everyday contexts — though it’s rarely used for emotional sensitivity (for which 敏感 is preferred). It often appears after the noun it modifies (e.g., 听觉很灵敏) or in predicate position with 是…的 structures.