Emily Dickinson Lexicon

A-CUTE', a. [L. acutus, sharp-pointed; Qu. from acuo, acus, or from the Oriental חד had or chad, sharp, Heb. Ch. Ar.]

1. Sharp at the end; ending in a sharp point; opposed to blunt or obtuse. An acute angle in geometry, is one which is less than a right angle, or which subtends less than ninety degrees. An acute angled triangle is one whose three angles are all acute, or less than ninety degrees each.
2. Figuratively, applied to mental powers; penetrating; having nice discernment; perceiving or using minute distinctions; opposed to dull or stupid; as, an acute reasoner.
3. Applied to the senses; having nice or quick sensibility; susceptible of slight impressions; having power to feel or perceive small objects; as, a man of acute eyesight, hearing, or feeling.
4. An acute disease, is one which is attended with violent symptoms, and comes speedily to a crisis, as a pleurisy; opposed to chronic.
5. An acute accent, is that which elevates or sharpens the voice.
6. In music, acute is applied to a tone which is sharp, or high; opposed to grave.
7. In botany, ending in an acute angle, as a leaf or perianth. – Martyn.