important
Something that is important is very significant, valuable, or necessary.
This is the most important part of the job.
It is important to study for your exams.
Be careful
Don't use ‘important’ to talk about a large sum or amount. Use considerable, substantial, or large.
Don't use ‘important’ to talk about a large sum or amount. Use considerable, substantial, or large.
He was paid a substantial sum of money for the information.
A considerable amount of rain had fallen.