WordNet sense 1 (a mark (') placed above a vowel to indicate pronunciation):

ague, acute accent

WordNet sense 2 (ending in a sharp point):

acuate, needlelike

WordNet sense 3 (having a point):

pointed

WordNet sense 4 (having or demonstrating ability to recognize or draw fine distinctions):

discriminating, incisive, keen, penetrating, penetrative, piercing, knifelike

WordNet sense 5 (extremely sharp or intense):

intense

WordNet sense 6 (keenly and painfully felt; as if caused by a sharp edge or point):

sharp

WordNet sense 7 (being in or verging on a state of crisis or emergency):

critical