A rajah is a king or ruler of an Indian state, especially in the older kingdoms of South Asia. You also see the spelling raja.

A rajahrajah is a king or ruler of an Indian state是印度某個邦的國王或統治者, especially in the older kingdoms of South Asia尤其是在南亞比較古老的王國裡。You也 see the spelling會看到 rajaraja這種拼法

In English it is mainly a history-and-story word now: you meet it in books about India, in old travel writing, and in tales, not as the everyday title of a leader in today’s news.

In English在英文裡 it is mainly a history-and-story word now這個字現在主要是歷史和故事裡用的字: you meet it你會在 in books about India, in old travel writing, and in tales關於印度的書、舊時的遊記，以及故事裡遇到它, not as the everyday title of a leader in today's news而不是今天新聞裡對領袖的日常稱呼

Though actually, the rank was not always “king” in the European sense — some rajahs ruled small states, and under the British Raj many were kept as princes under British power. English borrowed the word and then used it a little loosely for Indian royalty in general.

Though actually不過事實上, the rank這個位階 was not always “king” in the European sense並不總是等同於歐洲意義上的「國王」 — some rajahs有些rajah ruled small states只統治小邦國, and under the British Raj而在英屬印度的統治下 many很多rajah were kept as princes under British power被保留下來，當英國權力下的王公。English英文 borrowed the word借用了這個字 and then used it a little loosely for Indian royalty in general然後就比較鬆散地用它泛指印度的王室成員

It is not slang, but it is not a daily-life word.

It它 is not slang不是俚語, but it is not a daily-life word但也不是日常生活會用到的字