adjective

1. having a sharp point
2. keen or quick of mind; shrewd
3. sensitive to impressions acute hearing
4. severe and sharp, as pain, jealousy, etc.
5. severe but of short duration; not chronic: said of some diseases
6. very serious; critical; crucial an acute shortage of workers
7. shrill; high in pitch
8. of less than 90 degrees an acute angle
9. intensive (sense )

Etymology: L acutus, pp. of acuere, sharpen: see acumen