This is the 1881st most frequent Russian word.
пожаловались
"Complained."
In this sentence, the word 'пожаловались' is used as a past tense verb to mean that 'they' expressed dissatisfaction about the noisy neighbors.
Они пожаловались на шумных соседей.
They complained about the noisy neighbors.
The word 'пожаловались' here indicates that the students brought up their concerns to the teacher regarding challenging tasks.
Ученики пожаловались учителю на трудные задания.
The students complained to the teacher about the difficult assignments.
In this context, 'пожаловались' shows that the patients voiced their dissatisfaction with the extended waiting time.