Outwith
Shortened version of 'Outside of' which originated in Scotland as 'Ootwith'. Being a principle word of self-referential encoding it doesn't appear in any 'English' dictionary as it would no longer be 'Outwith' it anymore.
I'm sorry Madam, programming a neuromate robot to alter the 5HT3 update in the Dorsel Horn of the Hippocampus is outwith my knowledge as a plumber.