1. (used of a knife or other blade
not sharp
"a blunt instrument") 
blunt 
synonim: nieostry
2. (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") 
dense, dim, dull, dumb, obtuse, slow: : synonim: tępogłowy
3. (void of intelligence or thought
 "a vacant mind") 
vacant: : 
4. (terminating abruptly by having or as if having an end or point cut off
 "a truncate leaf"
 "truncated volcanic mountains"
 "a truncated pyramid") 
truncate, truncated: : synonim: ścięty
(człowiek) dense, dull
(nóż) blunt
 adj 
1.  (o narzędziu) blunt. 
2. (fig, o zmysłach) dull: ~ ból dull pain.
3. (fig, ograniczony umysłowo) dull
vacant
stupid: ~ wzrok vacant look
 ~ umysł dull mind
blunt adj., dull n
blunt, obtuse, dull mentally
DULL
OBTUSE
FAT
POINTLESS
STOLID
WITLESS
CRASS
DUD
DENSE
OPAQUE
adj dull, blunt
blunt, dull, obtuse
blunt
clueless
insipid
obtuseness
slow
slow-witted
thick-headed
vacant
vapid
wooden