This is the 12848th most frequent Russian word.
курьер
Courier.
Here, 'курьер' refers to a person acting as a delivery courier for parcels or goods.
Курьер принёс посылку.
The courier delivered the package.
Here, 'курьер' is used in an occupational sense, indicating the speaker's job.
Я работаю курьером в крупной компании.
I work as a courier in a large company.
In this sentence, 'курьер' refers generally to a service where a courier can be summoned for task execution.