Slow on the uptake (6)
'slow on the uptake' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for obtuse that I've seen before include "A 3dn between 90 and 180 degrees" , "Lacking in insight" , "To be thus blunt" , "Dense, dim about the angle" , "Orchestra; stripe" .)
'slow on the uptake' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for dense that I've seen before include "Thick, compact or crowded" , "Closely spaced or extremely stupid" , "Needs (anag) -- thick" , "Thick as undergrowth may be" , "Tightly packed - stupid" .)