In French, the word for ‘fat’ is ‘gras.’ This term can be used to describe someone or something that is overweight or to refer to fatty substances in food.
For example, you might say ‘un homme gros’ when referring to a ‘fat man’ or ‘un morceau de viande gras,’ which means ‘a piece of fatty meat.’ The adjective ‘gras’ agrees in gender and number with the noun it modifies, so if you’re describing a feminine noun, you would say ‘grasse.’
It’s also worth noting that while ‘gras’ is the direct translation, the connotation can vary in different contexts, so make sure to use it carefully in conversation.