Youngster gets point of dice (4)
I believe the answer is:
cube
'dice' is the definition.
(synonyms)
'youngster gets point' is the wordplay.
'youngster' becomes 'cub' (I've seen this in other clues).
'gets' says to put letters next to each other.
'point' becomes 'e' (compass point).
'cub'+'e'='CUBE'
'of' acts as a link.
(Other definitions for cube that I've seen before include "In maths, the third power of a quantity" , "Regular hexahedron" , "perhaps twenty-seven" , "1, 8, 27 or 64?" , "nine?" .)