Jaan-Nasheen | جَان نَشِین
Someone Placed Instead. (literal)
The eldest biological son. (common)
In terms of Tasawwuf, it is someone deputed to help fulfill his Sheikh’s responsibility of taking care of the Sufi Order on a spiritual level. That may mean different things in different Silsila based on their ways. A good example of this is the relationship of Hazrat Ali (rz) with Prophet Muhammad (saw). There were the three other Khulifa-e-Rashidun that were deputized to take care of the community in an Administrative and Political role. However, in the backdrop of each was Hazrat Ali (rz) as the Spiritual Heir of the Prophet (saw) to offer his blessings and guidance where possible. (context)