How to Spell acute

Middle English, borrowed from Latin acūtus "sharpened, pointed, having a violent onset, discerning, less than 90 degrees (of an angle)," from past participle of acuere "to sharpen, rouse, stimulate," probably derived from an otherwise unattested adjective stem acū- "sharp"; akin to acū-, acus "needle," a perhaps independently derived noun; further akin to Old Church Slavic osŭtŭ "thistle," Lithuanian ãšutas "hair of a horse's tail or mane"; all going back to the Indo-European base *heḱ- "sharp"