confirm
verb
uk/kənˈfɜːm/ us [ I or T ]
to make an arrangement or meeting certain, often by phone or writing:
confirm that So far ten people have confirmed that they will be attending the meeting.
When initial appointments are made over the telephone, these should also be confirmed in writing.
No contract exists until the company confirms by email that their order has been dispatched.
The group said it expected another $5 billion of orders to be confirmed soon.
[ T ]
to prove or say that something is true:
Britain's biggest dairy company yesterday confirmed 3,450 job losses.
They refused to confirm or deny speculation that the company was to close.
confirmation
noun [ C or U ]
It is essential to obtain confirmation in writing.
confirmation that Investors are looking for confirmation that the economy is picking up speed.