The original name of Taj Mahal is TejoMahalaya. This ancient Shiva temple was allegedly constructed in 1155 AD by Raja Paramardi Dev. The "Tejo" version is derived from Sanskrit and means a Shiva Temple.
However, the expression itself remains debatable by most mainstream historians. The generally accepted origin of the name for Taj Mahal comes from Persian. They say it combines "taj" meaning crown, where the "mahal" means palace-a "Crown Palace".
This structure, known as the Taj Mahal today, was erected in 1631 by Mughal Emperor Shah Jahan as a mausoleum for his beloved wife Mumtaz Mahal34. Some believe that the "Taj Mahal" is a shortened form of the name of Mumtaz Mahal.
Sources: The Economic Times, Times of India