Final answer:
The innermost sanctum in Hindu temple architecture is called the Garbhagriha.
Step-by-step explanation:
In Hindu temple architecture, the name of the innermost sanctum, which is typically the most sacred area where the deity of the temple resides, is known as the Garbhagriha. This term literally translates to 'womb-chamber' and is the part of the temple that adherents believe to be the core of the spiritual energy. The Garbhagriha is a small, usually cube-shaped room at the heart of the temple and is the focus of the rituals and prayers conducted in the temple.
It is the most sacred and important part of the temple, representing the divine presence of the deity worshipped in the temple. The Garbhagriha is usually a small, dark and windowless room that houses the main idol or image of the deity.