One way to spot the odd word here is to think about the situations in which each word would naturally be used in everyday language.
Three of the four words are everyday descriptive terms for domineering or self-centered behavior, while megalomania is a specialized term for a delusional condition, used far more narrowly than the others.
Therefore, the correct answer is Megalomania.
Choose the word that is closest in meaning to esoteric
The scientist's theory was initially met with _________, but later gained widespread acclaim after consistent experimental validation.