This is the 2458th most frequent Turkish word.
kardeşim
"My sibling" or "my brother/sister"; also used informally as "my friend" or "bro."
In this sentence, 'kardeşim' is used to refer to one's sibling.
Kardeşimle sinemaya gittik.
I went to the cinema with my sibling.
Here, 'kardeşim' is used as a term of address for a sibling.
Kardeşim, bana yardım eder misin?
Brother/Sister, can you help me?
'Kardeşim' is used here informally to address a friend or peer.