[syn: dense, dim, dull, dumb, obtuse, slow]
The Collaborative International Dictionary of English v.0.48:
Obtuse \Ob*tuse"\ a. [Compar. Obtuser; superl. Obtusest.]
   [L. obtusus, p. p. of obtundere to blunt: cf. F. obtus. See
   Obtund.]
   1. Not pointed or acute; blunt; -- applied esp. to angles
      greater than a right angle, or containing more than ninety
      degrees.
      [1913 Webster]
   2. Not having acute sensibility or perceptions; not alert,
      especially to the feelings of others; dull; stupid; as,
      obtuse senses. --Milton.
      [1913 Webster]
   3. Dull; deadened; as, obtuse sound. --Johnson.
      [1913 Webster] Obtuse-angled
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]
Moby Thesaurus II by Grady Ward, 1.0:
118 Moby Thesaurus words for "obtuse":
   abrupt, affectless, anesthetized, arctic, asleep, autistic,
   benumbed, bluff, blunt, blunt-edged, blunt-ended, blunt-pointed,
   blunt-witted, blunted, bluntish, boneheaded, callous, catatonic,
   chill, chilly, cloddish, cold, cold as charity, cold-blooded,
   coldhearted, cool, dead, deadened, dense, dim, dim-witted,
   dispassionate, doltish, dopey, drugged, dull, dull of mind,
   dull-edged, dull-headed, dull-pated, dull-pointed, dull-witted,
   dulled, dullish, edgeless, emotionally dead, emotionless, faired,
   fat-witted, frigid, frosted, frosty, frozen, gross-headed,
   heartless, heavy, hebetudinous, icy, immovable, impassible,
   impassive, imperceptive, impercipient, inexcitable, insensate,
   insensible, insensitive, insentient, insusceptible, loutish,
   lumpish, mentally retarded, nonemotional, numb, numbed, oafish,
   obdurate, objective, out of touch, passionless, pointless, rounded,
   self-absorbed, simple, slow, slow-witted, sluggish, smoothed,
   soulless, spiritless, stolid, thick, thick-brained, thick-headed,
   thick-pated, thick-skinned, thick-witted, thickheaded,
   thickskulled, unaffectionate, unedged, unemotional, unfeeling,
   unfelt, unimpassioned, unimpressionable, unloving, unpassionate,
   unperceptive, unpointed, unresponding, unresponsive, unsharp,
   unsharpened, unsusceptible, unsympathetic, untouchable, wooden