You should get familiar with the word "nakama" early because it's not just some shallow "friend" as shown in subs. "Friend" is too simple, generalizing and loses the deeper meaning of hierarchy/connections between characters. Nakama means "companion, fellow, friend, mate, comrade, partner, colleague, coworker, associate, member of the same category (circle, gang, family, class)" in japanese. In the world of One Piece nakama means all of them at once depending on the situation or relationship. This is important because when Arlong calls Nami a nakama he simply thinks of her as accomplice, coworker, partner in crime. While Luffy having his personal headcannon of what a nakama is, him calling Nami a nakama he's thinking friend, family, comrade, hence why he gets so pissed at Arlong calling Nami a nakama while treating her like a slave. "Friend/s" in japanese would be "tomodachi". And this is also important because Luffy draws a distinct line between who he thinks of as nakama and who is tomodachi. For example note that he calls Coby as "tomodachi" and never a "nakama", while those who are part of the crew (or who he decided he wants on the crew) a nakama.
i feel like i need to study japanese! haha but thanks a lot for explaining, the meaning of the words they are using, now i understand better the word 'Nakama' and how they use it on the show!
