Megalomania (from the Greek wor μεγαλομανία) is a historical term for behavior characterized by delusional fantasies of wealth, power, genius, or omnipotence - often generally termed as delusions of grandeur. The word is a collaboration of the word "mania" meaning madness and the Greek "megalo" meaning "very large", "great", or "exaggerated", thus combining to denote an obsession with, either in the form of irrational perceived need for or preoccupation with in one's own estimation having and/or obtaining, grandiosity and extravagance (especially in the form of great fame and popularity, material wealth, social influence or political power, or more than one or even all of the aforesaid) and accompanying complete desirous and bombastic abandon; a common symptom if not the key diagnostic feature of megalomania.