This is the 13070th most frequent Russian word.
марку
The Russian word "марку" is the accusative case of "марка," meaning "stamp" (postage) or "brand" (trade mark).
In this sentence, 'марку' is used metaphorically to mean one's reputation or standing in society.
Ты смог сохранить марку и доказать свою честность.
You managed to keep your reputation and prove your honesty.
'Марку' refers to an actual postage stamp, as used in philately.
Она отправила редкую марку коллекционеру.
She sent a rare stamp to the collector.
'Марку' symbolizes the standard or level of quality that one aims to maintain.