This is the 13568th most frequent Russian word.
начальников
"Начальников" means "chiefs" or "bosses" in English.
The word 'начальников' refers to multiple managers or bosses in the accusative plural case, showing the object of the request.
Начальников попросили появиться на собрании.
The managers were requested to attend the meeting.
Here, 'начальников' is in the accusative plural case, signifying the individuals being talked about.
Я видел, как начальников обсуждали в коридоре.
I saw the managers being discussed in the corridor.
In this sentence, 'начальников' is in the genitive plural case, indicating possession or relation to their orders.