The word 敏锐 is formed through the common Chinese morphological process of compounding, where two independent, semantically related characters are combined to create a new, nuanced meaning. The first character, 敏 (mǐn), carries the core idea of "quick", "agile", or "responsive", often referring to mental or physical speed. The second character, 锐 (ruì), means "sharp", "acute", or "penetrating", typically describing a physical or figurative edge. When paired, their meanings synergize: 敏 provides the quality of quickness and sensitivity, while 锐 adds the quality of sharpness and acuity. Together, they produce the compound meaning of "keen", "perceptive", or "sharp", specifically describing someone who is quick to observe, understand, and react with acute insight, thus forming a word whose meaning is more specific than the sum of its parts.