On a roll, one may have them in hand (4)
I believe the answer is:
'hand' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps you can see a link between them that I can't see?
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for dice that I've seen before include "Random number generators" , "Small cube" , "Cubes used in gambling" , "Take a risk" , "Numbered cube(s)" .)