This is the 6870th most frequent Russian word.
авиакомпания
Airline company.
The word 'авиакомпания' (airline) is used here as a subject noun to indicate the company that provides airline services.
Эта авиакомпания предлагает дешевые билеты.
This airline offers cheap tickets.
In this sentence, 'авиакомпания' is in the accusative case, indicating the object of the preposition 'в' (in, into), showing a relation to the company.
Мой друг устроился на работу в известную авиакомпанию.
My friend got a job at a well-known airline.
Here, 'авиакомпаний' is in the genitive plural form, used to describe the subset of all airlines they cooperate with.