the act of inspecting or verifying
"they made a check of their equipment"
"the pilot ran through the check-out procedure"
a counter in a supermarket where you pay for your purchases
"We waited in line at the checkout to scan our groceries before heading out of the store."
The process of checking out of a hotel, or the latest time to vacate a room in one.
"We need to leave our luggage at the front desk before the checkout time so we can catch our flight on time."
In plain English: Checkout is the place where you pay for your items and leave a store.
"Please wait at the checkout while I grab your bag."
Usage: As a noun, checkout refers to the specific deadline by which a guest must leave a hotel room before departure. It marks the end of your stay and determines when you are expected to settle any remaining balances or return keys.
The word checkout is a deverbial form derived from the phrase check out. It entered English as a noun describing the action of paying and leaving a store or hotel.