look up any word, like demisexual:
particularly egregious fabricated BS offered under the guise of fact, and then disclaimed as being 'opinion' when challenged and successfully refuted.

Tossing down the "openion" term indicates that you think something is not just 'opinion,' but has been represented as verifiable fact when it is the opposite.
It is my openion that Al Gore invented the internet.
by Annonymous August 06, 2004