megalomania
noun
meg·a·lo·ma·nia ˌme-gə-lō-ˈmā-nē-ə 
-nyə
1
: a mania (see mania sense 2a) for great or grandiose performance
an outburst of wildly extravagant commercial megalomania 
The Times Literary Supplement (London)
The Times Literary Supplement (London)2
: a delusional mental illness that is marked by feelings of personal omnipotence and grandeur
megalomaniac
ˌme-gə-lō-ˈmā-nē-ˌak
adjective or noun megalomaniacal
ˌme-gə-lō-mə-ˈnī-ə-kəl
adjective or less commonly megalomanic
ˌme-gə-lō-ˈma-nik
megalomaniacally
ˌme-gə-lō-mə-ˈnī-ə-k(ə-)lē
adverb 
Example Sentences
Their CEO has an arrogance that borders on megalomania.
Recent Examples on the Web What really changed things was not Trump, but Putin’s megalomania. Tom Mctague, The Atlantic, 2 July 2022 But such a policy, debatable only a few months ago, now seems almost impossible—destroyed by Putin’s bloody megalomania. Tom Mctague, The Atlantic, 4 Apr. 2022 Vladimir Putin’s territorial ambitions, his ruthless crackdowns of any and all dissent, his megalomania and determination to hold onto power at all costs were hardly being concealed. Alex Shephard, The New Republic, 25 Feb. 2022 Maybe megalomania is a key requirement for people to start a game-changing company. Bill Goodykoontz, The Arizona Republic, 21 Feb. 2022 The series, inspired by real events in the financial world, centers on narcissism, megalomania and double standards and was created by producers and showrunners Philipp Käßbohrer and Matthias Murmann. Naman Ramachandran, Variety, 8 Feb. 2022 Majorities are almost always composed of two or more parties, which tends to defuse extremism and megalomania. Ryan Cooper, The Week, 3 Nov. 2021 An afternoon’s stroll could bring you from a quaint neighborhood of neoclassical apartments to an austere postwar housing complex; from the fascist megalomania of Tempelhof Airport to the monumental Soviet grandeur of Karl-Marx-Allee. New York Times, 30 Nov. 2021 The treatments continued every day for months and may have amplified Hitler’s megalomania and self-delusion as the Allied armies advanced on Germany and tens of millions of soldiers and civilians perished. Joshua Hammer, The New York Review of Books, 8 Apr. 2021 See More
Tom Mctague, The Atlantic, 2 July 2022 But such a policy, debatable only a few months ago, now seems almost impossible—destroyed by Putin’s bloody megalomania. Tom Mctague, The Atlantic, 4 Apr. 2022 Vladimir Putin’s territorial ambitions, his ruthless crackdowns of any and all dissent, his megalomania and determination to hold onto power at all costs were hardly being concealed. Alex Shephard, The New Republic, 25 Feb. 2022 Maybe megalomania is a key requirement for people to start a game-changing company. Bill Goodykoontz, The Arizona Republic, 21 Feb. 2022 The series, inspired by real events in the financial world, centers on narcissism, megalomania and double standards and was created by producers and showrunners Philipp Käßbohrer and Matthias Murmann. Naman Ramachandran, Variety, 8 Feb. 2022 Majorities are almost always composed of two or more parties, which tends to defuse extremism and megalomania. Ryan Cooper, The Week, 3 Nov. 2021 An afternoon’s stroll could bring you from a quaint neighborhood of neoclassical apartments to an austere postwar housing complex; from the fascist megalomania of Tempelhof Airport to the monumental Soviet grandeur of Karl-Marx-Allee. New York Times, 30 Nov. 2021 The treatments continued every day for months and may have amplified Hitler’s megalomania and self-delusion as the Allied armies advanced on Germany and tens of millions of soldiers and civilians perished. Joshua Hammer, The New York Review of Books, 8 Apr. 2021 See More Word History
Etymology
New Latin
First Known Use
1885, in the meaning defined at sense 1
Medical Definition
megalomania
noun
meg·a·lo·ma·nia ˌmeg-ə-lō-ˈmā-nē-ə, -nyə
: a delusional mental illness that is marked by feelings of personal omnipotence and grandeur