"Considerable" means "a lot" or "not a small amount". Here are some examples:
There was considerable damage to the apartment when they moved out: scratches on the floor, stains on the walls, broken cabinet hinges, and so on.
We flew them in at considerable expense.
You could save a considerable amount of money by doing it yourself.
"Considerable" is a somewhat formal word. You can use it in business situations, in essays, in speeches, and so on.
The words that most commonly follow "considerable" are:
- a considerable amount
- a considerable number
- considerable attention
- considerable evidence