哥哥的英文單詞怎么寫?

old brother 老哥哥（指有了一定的年齡，年紀(jì)較大）
older brother和elder brother是近義詞，一樣的意思，即是“長(zhǎng)兄，哥哥”
另外：

elder/older
這兩個(gè)詞均是old的比較級(jí)，在用法上有所區(qū)別。elder本身也是形容詞。
elder表示“前輩的”、“年紀(jì)較長(zhǎng)的”，僅用于同一家庭成員的比較；older則不限于此。例如：
My younger son is five and my elder son is nine。我的小兒子5歲，大兒子9歲。
Tom is two years older than I.湯姆比我年長(zhǎng)兩歲。

elder在句中只用作定語，不作表語；older兩者皆可。例如：
My elder sister does her homework all by herself. 我的姐姐獨(dú)自做作業(yè)。
His elder son got married last week. 他的長(zhǎng)子是上星期結(jié)婚的。
I think his mother is older. 我認(rèn)為他的母親年齡大引起。

elder只能用來指人；older既可修飾人，也可修飾物。例如：
My elder brother joined the army when he was only fifteen.我哥哥年僅15負(fù)就參了軍。
This dog is older than any other dogs here.這條狗在這里是最老的一條。
I have a sister older than myself.我有位比我大的姐姐。
It is said Mr Chen is over ten years older than Mrs Li.據(jù)說陳先生比李女士大10多歲。
elderly是形容詞，“較老的”。

哥哥
[詞典]
brother;
[例句]她有一個(gè)雙胞胎哥哥和一個(gè)弟弟。
She
had
a
twin
brother
and
a
younger
brother.