Odorous means having a smell. On paper it is a calm, almost scientific word: it only says a smell is there. In real use it often hints that the smell is strong enough to notice, and not always pleasant — though it can still be used of flowers, spices, or warm bread. It is a little formal. Daily English more often says smelly (usually unkind, and usually bad), fragrant (nice), or “it smells of…”. Writers and scientists still like odorous because it does not rush to judge. If you need to say the smell is bad, English has malodorous, which builds “bad” onto this same word. You will not hear odorous much in the playground; you will meet it in books and in careful description.

有氣味的（偏書面；不自動等於好聞或難聞）