The term babu, also spelled baboo, is used in modern-day South Asia as a sign of respect towards men. It is a derivation of bapu which means father. The honorific "ji" is sometimes added as a suffix to create the double honorific "babuji" which, in northern and eastern parts of India, is a term of respect for one's father. "Babuji" can also be used as a term of respect for any respected elder or man. In some Indian states, "babu" is also used as a generic word of respect to address men, especially unknown ones, e.g., "Babu, can you help me?" In Bengali, "babu" is used as suffix to a person's name to show respect while calling him by name, e.g., "Sudarshan-babu, could you please come here!" The term "babu" may be suffixed to a person's name, but the term "babuji" is always used by itself.. In the Saurashtra language, "babu" may refer to a younger brother (sibling), or it can be used more broadly, similar to the terms fellow or bretheran, but, only in reference to those younger than oneself.
In British India, "babu" was a term used to describe a native Indian clerk. The word was originally used as a term of respect attached to a proper name, the equivalent of "mister", and "babuji" was used in many parts to mean "sir"; but when used alone without the suffix, it was a derogatory word signifying a semi-literate native, with a mere veneer of modern education.[1][2] In the early 20th century the term babu was frequently used to refer to bureaucrats and other government officials, especially by the Indian media;[3] in this sense the word hints at corrupt or lazy work practices.
"Babu" also means grandfather in Swahili, like "papu" in Greek.[4] In the Nepali and Bengali languages, it is a means of calling with love and affection to spouses or younger brothers, sons, grandsons, etc.