Fragrant means it has a smell, and the smell is a nice one. Flowers, soap, fruit, tea, rain on warm ground — if you lean in and think 'that smells good,' fragrant is the word. It is warm and a little bookish; in everyday talk people often just say it smells nice or it smells lovely. You would not use it for a bad smell. A garbage truck is smelly, not fragrant. Cooks and perfume ads love it. Though actually, it is about the smell being pleasant, not about how strong it is. A quiet hint of jasmine can be fragrant; so can a heavy bowl of spices. The noun is fragrance: the smell itself, or a perfume.