This is the 448th most frequent Polish word.
większość
The majority.
Here, 'większość' functions as a noun indicating the larger part of a group.
Większość ludzi lubi słuchać muzyki.
The majority of people enjoy listening to music.
In this context, 'większość' again works as a noun but refers specifically to tasks from a larger group.
Większość zadań została już wykonana.
The majority of tasks have already been completed.
Here, 'większość' relates to a portion of time, conveying the same idea of a dominant segment of a whole.