keen

adjective
  1. Having or showing eagerness or enthusiasm. adjective
    She is keen to start her new job.
    He was keen on learning the guitar.
  2. Sharp or penetrating, in particular. adjective
    The keen blade sliced through the rope easily.
    He has a keen sense of smell.
  3. Intellectually alert; having a quick and penetrating mind. adjective
    She has a keen mind for solving complex problems.
    His keen insights into the market trends helped the company succeed.
  4. Highly developed; acute. adjective
    Dogs have a keen sense of hearing.
    He has a keen eye for detail.
  5. A lamentation for the dead uttered in a loud wailing voice or sometimes in a wordless cry. noun
    The mourners gathered to keen for the deceased.
    The sound of keening filled the air at the funeral.