This is the 17343rd most frequent Russian word.
таксистом
"Таксистом" means "taxi driver" in the instrumental case in Russian.
In this sentence, 'таксистом' is used as an instrumental case form of the noun 'таксист' (taxi driver), indicating the role or occupation being performed by the subject.
Мой брат работает таксистом в большом городе.
My brother works as a taxi driver in a big city.
Here, 'таксистом' is in the instrumental case, used to indicate the person with whom the subject interacted during the action.
Я общался с таксистом по дороге домой.
I spoke with the taxi driver on my way home.
'Таксистом' is employed in the instrumental case to describe the position or role (a taxi driver) the subject is being offered.