This is the 11613th most frequent Russian word.
жалоб
"Жалоб" is the genitive plural form of "жалоба," meaning "complaint(s)."
In this context, 'жалобу' means a formal or informal complaint made towards an issue.
Он подал жалобу на шумных соседей.
He filed a complaint about the noisy neighbors.
Here, 'жалоб' refers to verbal expressions of dissatisfaction or grievances.
Её слова были полны жалоб и обид.
Her words were full of complaints and grievances.
In this usage, 'жалоб' is used in the sense of submitted cases or noted expressions of concern or dissatisfaction.