n) adj.keen·er, keen·est1. Having a fine, sharp cutting edge or point. 2. Having or marked by intellectual quickness and acuity. See Synonyms at sharp. 3. Acutely sensitive: a keen ear. 4. Sharp; vivid; strong: "His entire body hungered for keen sensation, something exciting"(Richard Wright). 5. Intense; piercing: a keen wind. 6. Pungent; acrid: A keen smell of skunk was left behind. 7.a. Ardent; enthusiastic: a keen chess player. b. Eagerly desirous: keen on going to Europe in the spring.