Familiar term for one's elder brother. It is more casual, rough, or affectionate than 兄, and may carry a respectful feeling toward the older brother rather than being polite speech.
My older brother works in Tokyo.
Big bro, I need to ask you about something.
senior; older-brother figure
Used for a senior or respected older-brother-like figure in a group. It sounds familiar and often masculine; in ordinary school or workplace contexts, 先輩 is the safer neutral word.
Everyone affectionately calls the senior at work 'Aniki.'
older man; older guy
Colloquial way to refer to a man older than oneself, often with a rough, streetwise, or familiar flavor rather than a neutral description of age.
A tough-looking older guy was standing in front of the shop.
His juniors looked up to him and called him 'big brother.'
He's like a big brother to me.
先輩 is the neutral, widely appropriate word for a senior in school or work, while 兄貴 used this way is slangier and often masculine.
兄貴 is the standard word for an older brother or a respected senior male, while ニキ is internet slang derived from it, used as a casual suffix for a trusted online peer.
兄貴 is a rougher, more masculine or gang-style term for an older brother compared to the warmer, more general 兄さん.
兄貴 is a rougher, more masculine way to say 'older brother', often used among young men, whereas 兄ちゃん sounds more childlike and affectionate.
senior group member; leader among peers · like an older brother; big brother
Standard kanji spelling. The word is familiar and often masculine or rough-sounding, but can also imply affection or respect.
Attested katakana spelling. Often emphasizes a colloquial, affectionate, manga-like, or rough tone.
Written with 兄, 'elder brother,' and 貴, a character associated with honor or respect. The spelling reflects the word's respectful or affectionate older-brother nuance; the exact historical development is not specified.