Sui generis
In sociology, the "sui generis" is what has been externalized, then internalized in the overall public and becomes a part of society that simply exists in its construct. It is not something that is not thought to have been created, because it is imbedded in everyone's way of thinking and being. Instances include the idea of love, or going to school, or clothing belonging to a specific gender. These examples are "sui generis" for they simply exist in society and are widely accepted without thoughts of where they come from or how they were created.
Svecchamrityu (Iccha-mrityu)
Svecchamrityu (Sanskrit: स्वेच्छामृत्यु) {Sva (self) + iccha (will) + mrityu (death)} is an adjective which means - having death at one’s own power or dying at one’s own will It is also called Iccha-mrityu (इच्छा मृत्यु) meaning self-willed death but it is not to be confused with immortality or self-inflicted death. Shantanu had granted to his son Gangaputra Devavrata, also known as Bhishma, the supernatural power of Svecchamrityu. Mahabharata records that Bhishma did choose the time and manner of his own death.