This is the 9419th most frequent Russian word.
трейси
"Трейси" is a transliteration of the English name "Tracy." It does not have a distinct meaning in Russian.
In this sentence, 'Трейси' is used as a proper noun, likely someone's name.
Трейси пришла сегодня на работу позже обычного.
Tracy came to work later than usual today.
Here, 'Трейси' again refers to a personal name, possibly an author.
Я читаю книгу про авторку по имени Трейси.
I am reading a book about an author named Tracy.
'Трейси' in this sentence functions as a proper name, identifying a specific individual who is a friend.