"Grand" means large, big, tall. It also means great but it means a quantity– "Great quantity". For that great(quality) there's another word in french–Génial. For example: Ton pere est grand-Your father is tall/big. Ton pere est genial-Your father is great.
Can you explain why large or big aren't accepted here? It only seems to accept tall...
I think when you say grand for people, it refers to tall; for big as in fat we'd probably use "gros". Also to reply to the original question... figurative meaning of French words is taken when the adjective precedes the noun. For example: un grand homme= a great man. un homme grand= a tall man. HTH.
So the translation: your father is big doesn't count? This is wayy too picky. Grand can mean big too!