aguzar

To sharpen, literally (aguzar un lápiz, to sharpen a pencil, more common in some regions than sacar punta) or figuratively — to heighten a sense or one's wit: aguzar el oído, aguzar el ingenio. The figurative senses are the ones learners run into most in everyday reading.

• Aguzó el oído para escuchar mejor la conversación. — He pricked up his ears to hear the conversation better.
• Hay que aguzar el ingenio para resolver este acertijo. — You have to sharpen your wits to solve this riddle.
• El carpintero aguzó la punta del cincel. — The carpenter sharpened the tip of the chisel.

Only learning the literal "sharpen an object" meaning — aguzar el oído/la vista/el ingenio (sharpening a sense or one's wits) are the phrases learners actually encounter most in books and articles.

• expression "Aguzar el oído" — A common fixed expression meaning to listen closely or attentively, as if straining to catch a faint or distant sound — the Spanish equivalent of English's "to prick up one's ears."