Humpty Dumptyism

Etymology
From the fictional character Humpty Dumpty in Lewis Caroll's Through the Looking-Glass, who, when asked what he meant by "glory", replies "I meant 'there's a nice knock-down argument for you!'". Alice protests that this isn't the meaning of "glory" and Humpty Dumpty replies "When I use a word it means just what I choose it to mean — neither more nor less."

Noun

 * 1)  The practice of insisting that a word means whatever one wishes it to.