acute vs obtuse

acute is a noun but obtuse is not a noun.

Word	Noun	Adjective	Verb	Adverb
acute	Yes	Yes	No	No
obtuse	No	Yes	No	No

acute (noun)	obtuse (noun)
a mark placed above a vowel to indicate pronunciation

acute (adjective)	obtuse (adjective)
having or experiencing a rapid onset and short but severe course	of an angle; between 90 and 180 degrees
of an angle; less than 90 degrees	(of a leaf shape) rounded at the apex
of critical importance and consequence	slow to learn or understand; lacking intellectual acuity
having or demonstrating ability to recognize or draw fine distinctions	lacking in insight or discernment
ending in a sharp point
extremely sharp or severe