obtuse
ob-tuse
adjective
An angle measuring more than 90 degrees but less than 180 degrees.
"The triangle contained an obtuse angle."
adjective
Slow to understand or perceive; dull-witted and insensitive.
"He was too obtuse to grasp the joke."
Thesaurus
Synonyms: unsubdivided, simple, purblind, undiscerning, dumb, dull, slow, stupid, dim, dense
Antonyms: acute