nosism (NO-siz-em) noun
The use of 'we' in referring to oneself.
[From Latin nos (we).]
As it's often used by editors, it's also known as the "editorial we". It's also called "the royal we" owing to its frequent use by royalty. Mark Twain once said, "Only kings, presidents, editors, and people with tapeworms have the right to use the editorial 'we'."
-Anu Garg (words at wordsmith.org)
"We must avoid both egoism and nosism in order to realize the glory of
humanity." J. Odera Oruka; Philosophy, Humanity and Ecology; Diane Publishing; 1996.
Mark Twain makes me laugh!