1. sharp (knife, claws, etc.); pointed
2. sharp (pain, tone, etc.); acute; stabbing; cutting (remark, criticism, etc.); stinging; biting; fierce (attack); pointed (question, look, etc.); piercing (gaze); shrill (sound)
3. keen (intuition, sense of smell, etc.); acute; sharp (eye, mind, etc.); astute; shrewd; discerning; penetrating (insight, question, etc.); perceptive