A familiar/casual way to refer to one's older sister (equivalent to 'older sis').
ねえちゃん、今日の宿題手伝ってくれる？
Sis, can you help me with today's homework?
子どもは泣きながら姉ちゃんを探していた。
The child was crying while looking for his older sister.
あの家の姉ちゃんはとても気さくな人だ。
The older sister at that house is a very friendly person.
Informal usage referring to a girl or young woman; a casual way to mention a female (sometimes used regionally or colloquially).
あそこの姉ちゃん、料理が上手そうだね。
That girl over there looks like she's good at cooking.
祭りで浴衣を着た姉ちゃんたちが集まっていた。
Girls wearing yukata had gathered at the festival.