This is the 12778th most frequent Russian word.
критику
"Criticism."
The word 'критику' is used in its accusative singular form to denote the object of the action of the verb 'принимаю'.
Я принимаю критику, чтобы стать лучше.
I accept criticism to become better.
The word 'критику' here is part of a descriptive phrase 'конструктивную критику', showing the type of criticism addressed.
Он ответил на конструктивную критику коллег.
He responded to constructive criticism from colleagues.
Although 'критику' itself is not present here, this demonstrates a related form, 'Критика', which is the nominative singular form serving as the subject of the sentence.