Acute definition

Okay, so I was looking at the vocab list #5 and one of the last words had 'acute' in the definition and I didn't know what this word mean, to be honest, after looking it up I still don't understand. I associate it with the geometrical acute angle but obviously it's not the same. I have a dilemma. If anyone can further describe the definition so I can understand I'd be grateful.

via Google

a·cute

əˈkyo͞ot/

adjective

1. 1.

   (of a bad, difficult, or unwelcome situation or phenomenon) present or experienced to a severe or intense degree.

   "an acute housing shortage"

   synonyms:

   severe, critical, drastic, dire, dreadful, terrible, awful, grave, bad,serious, desperate, dangerous "acute food shortages"
2. 2.

   having or showing a perceptive understanding or insight: shrewd.

   "an acute awareness of changing fashions"

   synonyms:

   astute, shrewd, sharp, sharp-witted, razor-sharp, rapierlike, quick,quick-witted, agile, nimble, clever, intelligent, brilliant, keen, smart,canny, discerning, perceptive, perspicacious, penetrating, insightful,incisive, piercing, discriminating, sagacious, wise, judicious; More