In French, the word important can be similar to the word in English, but also can mean important in relation to size, amount, quantity.
You may know that a VIP is a very important person. But it would be strange to say in English “a very important accident” or “a very important sum of money”.
What words go with “important”? The following words live quite happily with “important”
meeting, person, phone call, message, ingredient, part, role
Instead of “important”, use the following pairs
there was a lot of traffic (la circulation était important)
a serious accident
A significant unemployment rate (taux de chomage)
A substantial amount of money