unessential

adjective2

1. •
   Not essential.

   • [He was] moved rather with Pity than Indignation towards the Persons of those, who differed from him in the unessential Parts of Christianity. — 1716
2. •
   Void of essence, or real being.

   • These [gates] past, if any pass, the void profound Of unessential Night receives him next Wide gaping, and with utter loss of being Threatens him, — 1667