From WordNet (r) 3.0 (2006):
obtuse
adj 1: of an angle; between 90 and 180 degrees [ant: acute]
2: (of a leaf shape) rounded at the apex
3: lacking in insight or discernment; "too obtuse to grasp the
implications of his behavior"; "a purblind oligarchy that
flatly refused to see that history was condemning it to the
dustbin"- Jasper Griffin [syn: obtuse, purblind]
4: slow to learn or understand; lacking intellectual acuity; "so
dense he never understands anything I say to him"; "never met
anyone quite so dim"; "although dull at classical learning,
at mathematics he was uncommonly quick"- Thackeray; "dumb
officials make some really dumb decisions"; "he was either
normally stupid or being deliberately obtuse"; "worked with
the slow students" [syn: dense, dim, dull, dumb,
obtuse, slow]