extraordinary
adjective
uk/ɪkˈstrɔːdənəri/ usvery unusual, special, or unexpected:
extraordinary accomplishment/achievement/effort It's an extraordinary accomplishment to be able to run a successful project for 40 years.
After a rough start, this year is shaping up to be a year of extraordinary growth for the company.
[ before noun ] ACCOUNTING
used to describe a large cost or loss that does not happen regularly:
The oil spill was handled as an extraordinary expense - a non-recurring, one-time event.
[ before noun ]
used to describe something that does not happen regularly but that is arranged for a special purpose:
They convened an extraordinary meeting of shareholders to discuss the issue.