This is the 11316th most frequent Russian word.
депутатом
"Депутатом" means "a deputy or member of a legislative body."
Here, 'депутатом' denotes an individual who has acquired an official political position as a result of an election.
Он стал депутатом после выборов.
He became a deputy after the elections.
In this sentence, the instrumental form 'депутатом' is used to show the role or function he assumes in his professional capacity.
Работая депутатом, он принимает важные решения.
Working as a deputy, he makes important decisions.
Here, 'депутатом' represents a specific individual who holds the position and is recognized by the community.