WordReference Random House Unabridged Dictionary of American English © 2025
gra•num 
(grā′nəm),USA pronunciation n., pl. -na (-nə).USA pronunciation 
            - Drugs(in prescriptions) a grain.
 - Plant Biology[Bot.]one of the structural units of a chloroplast in vascular plants, consisting of layers of thylakoids.
 
- Latin
 
'granum' also found in these entries (note: many are not synonyms or translations):