Definition - The practice of referring to yourself as we.

Example -

(1) We are not amused. (Queen Victoria)
(2) We are not Queen Victoria. (Queen Elizabeth)

Etymology -
The word derives from the Latin nos, we.

Oxford English Dictionary -
Its first citation is from 1829:
"We will be consistent according to the fashionable virtue of the day in nos-ism."
(Examiner 162/1)

Please comment